gt5 reads the output of du, compares it with a du log saved on the previous invocation, converts it into HTML, and opens the results with a text browser. It is an (even better) textmode alternative to xdiskusage, which is already in portage. It is a shell-script, released under GPL, hosted on sourceforge and only depends on gawk and a textbrowser ('links' is recommended, see http://gt5.sourceforge.net/browsers.html why)
Created attachment 77309 [details] gt5-1.3b.ebuild
Looks like 1.3b fixes a security bug. From changelog: 15.06.2006 version 1.3b * fixed quoting in two trap statements which could be used by local users to run arbitrary code as the user running gt5
Thanks for the ebuild, I've bumped it to 1.3d and did some small changes :)