I’ve been using TraxTime from Spud City Software (is that a great name or what?) for yonks to track billable time. TraxTime is a Windows program which runs on a single computer. (There is also a multi-user version which works on a LAN, and allows for aggregate reporting). Now that I’ve got a Mac, though, I’ve been looking at web-based time tracking. The problem with Web-based time tracking is that you need to have an open browser running.
But now, Harvest includes widgets for both the mac and the pc which interface with their web-based tracking application. So you can run cross-platform outside of a browser. It has passed the five-minute test.