Toggl is a great tool for time tracking. Specially if you work for multiple clients and/or projects at the same time.
Toggl provides a REST/JSON API and several samples in various programming languages. But one thing was missing a Java wrapper for the Toggl API.
So I decided to create one. You can find the project on Google code. It's called jtoggl.
If you have any suggestions or find any problems please let me know. You can use the issue tracker.