I made an ebuild for Kerry, a KDE search interface for beagle (based on best). If installed, it appears as an icon in the systray. You can activate it via mouse, with F12 or (Ctrl-) Alt-Space.

The only sources I found for this program were on the opensuse servers so the ebuild downloads the source rpm form opensuse and converts it with rpm2targz, so app-arch/rpm2targz is a dependency of the kerry-0.07.ebuild.

If you install beagle for the first time to use it with KDE only, you don't need the gtk use flag which adds dependencies for a bunch of gnome stuff.
For more information about installing beagle on Gentoo read the Gentoo Installation article form the Beagle Wiki.