Time Trek is free cross platform time tracking software. Time Trek works like a punch clock:

- Name the client
- Describe the specific task at hand
- Punch in
- Punch out for a break
- Punch back in after a break
- Print "invoice" reports

... All in a small, neat window.

An ideal time clock software for simple freelance or consulting projects for Mac or PC.

http://www.gieson.com/Library/projects/utilities/timetrek/index.html