Klok track all your time spent on projects, client work, and pretty much anything else you're looking to track--and does it beautifully. The Klok application features a handsome interface, impressive tracking tools, a reports view for analyzing your time in pretty charts, and simple tools for exporting your time sheet. Whether you work freelance or consulting--or you just want to keep a closer eye on where your time goes--Klok does the trick nicely.
Note: This link takes you to the vendor's site, where you can download the latest version of the software. This program is donationware. It is free to try, but the author accepts and encourages donations towards further development.