Low-Budget Network-Based Time Tracking Software?

0verkill asks: "I have been charged with the task of finding time tracking software to replace our current manual punch card method of tracking our employees time spent on the job. I would appreciate any feeedback/suggestions from anyone who has experience implementing and/or maintaing this software. Here are the criteria that I'm working with currently: I have a spending range of up to $400-$500; the software should support clocking in/out from more than one network attached workstation; basic report generation -- nothing too fancy but something that covers all the basics; and finally something that is resistant to time tampering (maybe software that could obtain an official time from our servers)."