ClipIt is a lightweight, fully featured GTK+ clipboard manager. It was forked from Parcellite (http://parcellite.sourceforge.net), adding additional features and bugfixes to the project. Please also see http://clipit.rspwn.com/
Clipboard managers can be useful when doing a lot of copy/pastes. I noticed Clipit as part of the standard Fedora 19 install in one of my virtual machines. They had no rpm package for Fedora 14 so I compiled the source and it works great. It’s a nice no nonsense useful tool.