emerge --info on first machine:
Portage 2.1.2.3 (default-linux/x86/2006.0, gcc-4.1.2, glibc-2.5-r1, 2.6.19-rc6-mm2 i686)
=================================================================
System uname: 2.6.19-rc6-mm2 i686 AMD Athlon(tm) 64 Processor 3000+
Gentoo Base System release 1.12.10
Timestamp of tree: Sat, 14 Apr 2007 01:50:01 +0000
distcc 2.18.3 i686-pc-linux-gnu (protocols 1 and 2) (default port 3632) [disabled]
dev-java/java-config: 1.3.7, 2.0.31-r5
dev-lang/python:     2.3.6, 2.4.4
dev-python/pycrypto: 2.0.1-r5
sys-apps/sandbox:    1.2.18.1
sys-devel/autoconf:  2.13, 2.61
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils:  2.17
sys-devel/gcc-config: 1.3.16
sys-devel/libtool:   1.5.23b
virtual/os-headers:  2.6.20-r2
ACCEPT_KEYWORDS="x86 ~x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-Os -march=athlon-xp -pipe "
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/lib/fax /usr/share/X11/xkb /usr/share/config /var/service /var/spool/fax/etc"
CONFIG_PROTECT_MASK="/etc/X11/xinit/xinitrc /etc/cups /etc/cups/cupsd.conf /etc/env.d /etc/env.d/java/ /etc/gconf /etc/init.d/net.eth0 /etc/java-config/vms/ /etc/modules.autoload.d/kernel-2.6 /etc/portage /etc/rc.d /etc/revdep-rebuild /etc/samba/ /etc/terminfo /etc/texmf/web2c /etc/vsftpd/"
CXXFLAGS="-Os -march=athlon-xp -pipe "
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig confcache distlocks keepwork metadata-transfer parallel-fetch prelink sandbox sfperms splitdebug strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo"
LANG="pl_PL"
LC_ALL="pl_PL"
LINGUAS="pl en"
MAKEOPTS="-j3"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --filter=H_**/files/digest-*"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/distcc_portage"
SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage"
USE="# & 3dnow 3dnowex 3dnowext KDE X Xaw3d a52 aac acl acpi ada aim alsa amd amr and applications artworkextra asf asm audio audiofile bash-completion bcmath bdf beagle berkdb bidi binfilter bitmap-fonts bl blender-game bluetooth burner bzip2 bzlib cairo cdparanoia cdr cle266 cli codecs communicators compilers compression cpdflib cracklib crypt cscope css ctype cups cvs cvsgraph daemons dbus desired devices dga divx4linux djvu dlloader dmi doc dri dts dv dvb dvd dvdr dvdread dvi dxr3 edl emboss encode etc examples exif expat extensions external f77 fam fat fbcon features ffmpeg fftw firefox flac flash font-server fonts foomaticdb fortran ftp fuse gaim gb gcj gd gdb gdbm gg ggi gif gimp gimpprint ginac glade glibc-compat20 glibc-omitfp glitz glx gmp gnokii gnuplot gnutls gphoto2 gpm graph/video graphics gs gtk gtk2 gui gvim gzip hal hfs iconv icq icu id3 idea idn iksemel image imagemagick imap imlib innodb iodbc iproute2 ipv6 ipv6arpa irc irda irmc irssi isdnlog j2ee jabber java javacomm javascript jbig jfs john jp2 jpeg jpeg2k kde kdeenablefinal kdehiddenvisibility kdepim kdexdeltas kdgraphics lame language latex lcms lesstif libcaca libedit libg++ libs libwww live lua lzo lzw mad maildir matroska md5sum midi mikmod mime mimencode mjpeg mmap mmx mmx2 mmxext mng mnogosearch mod mono motif mouse mozdevelop mozsvg mp3 mp4 mp4live mpd-mad mpeg mpeg2 mpeg4 mplayer mpx msn musepack nautilus ncurses neXt net network nforce2 nfs nls nntp nodrm not nptl nptlonly nsplugin ntfs ntlm nvidia nvtv objc objc++ octave offensive ogg openal openexr opengl openssh osc other pam pango pascal pcntl pcre pda pdf pdfkit peech perl pheaders plotutils png posix povray ppds pppd print processor programming protocols python qt qt3 qt4 quicktime rar real realmedia reflection reiser4 reiserfs rle samba sasl scanner scp screen sdk sdl seamonkey security sendfile serial session sftp sftplogging shaper shorten simplexml skey slang slp smime sms sndfile sockets socks5 sound sourceview sox speedo speex spell spl sql sse sse2 sse3 ssh ssl subp subtitles subversion support svg svga swf sysfs system sysvipc szip t1lib tcl tcltk tcpd tetex tga theora threads tiff tlen transcode truetype truetype-fonts type1 type1-fonts ucs2 udev unicode unknown usb useful userlocales utf8 v4l v4l2 valgrind vcd vdr vfat video vidix vim vim-with-x voice vorbis win32codecs wma wma123 wmf wxwindows x264 x86 xanim xfs xine xinerama xml xml2 xmlreader xmlrpc xmlwriter xorg xpm xprint xv xvid xvmc yahoo yp yv12 zip zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1 emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mulaw multi null plug rate route share shm softvol" ELIBC="glibc" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="pl en" USERLAND="GNU" VIDEO_CARDS="nvidia nv"
Unset:  CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LDFLAGS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

emerge --info on second machine:
Portage 2.1.2.3 (default-linux/x86/2006.0, gcc-4.1.2, glibc-2.5-r1, 2.6.20-gentoo i686)
=================================================================
System uname: 2.6.20-gentoo i686 Intel(R) Pentium(R) 4 CPU 3.20GHz
Gentoo Base System release 1.12.10
Timestamp of tree: Tue, 10 Apr 2007 08:00:09 +0000
dev-java/java-config: 1.3.7, 2.0.31-r5
dev-lang/python:     2.4.4
dev-python/pycrypto: 2.0.1-r5
sys-apps/sandbox:    1.2.18.1
sys-devel/autoconf:  2.13, 2.61
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils:  2.17
sys-devel/gcc-config: 1.3.15-r1
sys-devel/libtool:   1.5.23b
virtual/os-headers:  2.6.20-r2
ACCEPT_KEYWORDS="x86 ~x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-Os -march=pentium4 -pipe"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/share/X11/xkb /usr/share/config"
CONFIG_PROTECT_MASK="/etc/env.d /etc/env.d/java/ /etc/gconf /etc/java-config/vms/ /etc/php/apache1-php5/ext-active/ /etc/php/apache2-php5/ext-active/ /etc/php/cgi-php5/ext-active/ /etc/php/cli-php5/ext-active/ /etc/revdep-rebuild /etc/terminfo /etc/texmf/web2c"
CXXFLAGS="-Os -march=pentium4 -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="buildpkg candy ccache distlocks metadata-transfer moo parallel-fetch sandbox sfperms strict userpriv usersandbox"
GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo"
LANG="pl_PL"
LC_ALL="pl_PL"
LINGUAS="pl en"
MAKEOPTS="-j3"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --filter=H_**/files/digest-*"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X Xaw3d aac acl acpi aiglx aim alsa apache2 apic arts audiofile avi bash-completion bcmath berkdb bidi bitmap-fonts bluetooth bonobo bzip2 cdparanoia cdr cid clflush cli cmov cpdflib cracklib crypt ctype cups cx8 dbus de devhelp dga divx4linux doc dri dts dv dvb dvd dvdr dvdread eds emboss encode examples exif extrafilters ffmpeg fftw flac flash foomaticdb fortran fortranftp fpu ftp fxsr gcj gd gdbm ggi gif gimp ginac glut gmp gnutls gphoto2 gpm gs gtk gtk2 hal howl ht hyperwave-api iconv icq ieee1394 imagemagick imap imlib ipv6 irda isdnlog java javascript jpeg jpeg2k jpg kde kdeenablefinal kdehiddenvisibility libg++ libwww lirc lzo mad matroska mca mce mhash midi mikmod mime ming mjpeg mmap mmx mng motif mozilla mp3 mpeg msn msr mtrr multislot musepack mysql mysqli ncurses nls nptl nsplugin objc offensive ogg oggvorbis openal opengl oss pae pam pat pbe pcntl pcre pdf pdflib perl pge php plotutils png posix ppds pppd pse pse36 python qt qt3 qt4 quicktime readline real reflection samba scanner sdl sep session sndfile source sox speex spell spl sql ss sse sse2 ssl subversion svg sysvipc szip tcltk tcpd tetex theora threads tiff tm truetype truetype-fonts tsc type1-fonts unicode usb vcd vidix vme vorbis win32codecs wmf wxwindows x86 xine xinerama xml xml2 xorg xosd xpm xprint xtpr xv xvid xvmc yahoo zip zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1 emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mulaw multi null plug rate route share shm softvol" ELIBC="glibc" INPUT_DEVICES="mouse keyboard" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="pl en" USERLAND="GNU" VIDEO_CARDS="radeon ati"
Unset:  CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LDFLAGS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY