I've just emerged gftp and saw that using gtk2 use flag it will compile against gtk2. I browsed through the docs, but nowhere gtk2 is documented. it works though :) I can imagine that there are more new use flags -> please update the corresponding docs.
root@rux0r root # grep gtk2 /usr/portage/profiles/use.desc gtk2 - use gtk+-2.0.0 over gtk+-1.2 in cases where a program supports both. beware that gtk+-2 support can be bad.
well, I can see it there, no problem. but look at http://www.gentoo.org/doc/use-howto.html. that's the place where 90% of the people are looking for.
should appear at next website update