To track my time I used hamster-applet with the previous version of Fedora and I really liked it. It integrates perfectly with gtg.
This project hasn’t be ported to Fedora 18, see bug 882788. I decided then to package the latest version of the project.
The git repo is available here.
You can see some screenshots here.
If you enjoy or discover this cool project, I’m happy to make it available for Fedora 18.
[UPDATE] I added the packages for F19 😉