MinuteWorx has been great for us. We have about 50 employees spread over 8 offices, and we needed a solution that was simple and would work from anywhere (including for work from home people). MinuteWorx has been great, and the tech support is awesome as well. It is very inexpensive. I would HIGHLY recommend it. It also looks like they are continuously improving the software (the UI for the punch clock itself looks much nicer now).
The only reason I give it 4 instead of 5 stars is because:
a) Billing could be a little more automated (they email me an invoice) - although in their defense I haven't asked them for more automated options, they may well have them available
b) The punchclocks depend on cookies (unless you have Static IPs) . . . so if someone accidentally (or intentionally) clears their cookies, the punchclock has to be set up again. There are workarounds to prevent this on some browsers. This is more of an issue on shared computers. Honestly it isn't a huge issue, because you can train users appropriately, and fixing the problem only takes a couple minutes at most. It has only happened to us a few times.
Anyway, we love MinuteWork, again, HIGHLY recommended.