If you're in the mood to beat someone up while you're at the office, you no longer have to do something that will get you thrown in jail. You might get fired, but that's probably going to happen anyway, right? You might as well make use of the company's bandwidth.

Thanks to the wonders of Macromedia Flash and Director, you can now play beat `em ups in your browser. As an example, I like the nostalgicly titled Way of the Exploding Stick. If you prefer something more traditional, you might like to try X-Men vs. Street Fighter. Yes, just like the original CapCom game. Login as “Player” with no password if you don't want to register.

If beat `em ups aren't your cup of tea, why not try a rally game where you get to design the track. Any game with a mini has too be fun. I think it's a rule or something.