This is a unit conversion handler for gnome-extra/deskbar-applet which wraps sci-calculators/units. Ebuild will be posted shortly.
Committed ebuild to Sunrise: http://gentoo-sunrise.org/cgi-bin/trac.cgi/browser/sunrise/x11-plugins/deskbar-handlers-converter/deskbar-handlers-converter-1.05.ebuild It should make its way to the reviewed tree sometime in the next few hours, and will then be available from the Sunrise overlay.
It's no longer fetchable.