This is a Qt-based serial (RS-232) terminal program that has been in use for about a year. I think it would be useful for Gentoo users. I am the author of the QST program, and a longtime Gentoo user, but have never figured out how to create an ebuild.
If you want to learn how to write ebuilds, read the development guide http://devmanual.gentoo.org/ and come to #gentoo-dev-help on irc.freenode.net