said it once before but it bears repeating
I've mentioned Tor before in the context of BitTorrent, but now that I'm on a contract site, it's worth talking about its more traditional use: anonymous websurfing.
It's really, really easy to see the contents of traffic on the same subnet as your PC. Practically speaking, you're likely to be on the same subnet if you're plugged into the same router, and you're likely to share a router with other folks in your department, floor, office or building, depending on the size of your corporate overlords.
Don't believe me? Go download Ethereal and fire it up. It's not the most user-friendly app in the world, but you should be able to wrestle it into coughing up some packets, and if you sift through them you'll be able to find your coworkers' IM conversations, web surfing habits, and (frequently) email. Creepy, right?
Well, you can be sure that your company's IT department can do the same thing, only with a lot less effort. Do you really want them peering over your virtual shoulder? Of course not. I know what you've been looking at, you pervert.
So what's to be done? Simple. Encrypt all your traffic, for one. For another, send it zipping randomly throughout the internet so that your office geek can't see who your PC is talking to. This is exactly what Tor does. Go here and follow the instructions. You just need to install Tor and a piece of software called Privoxy. Both are free, and both are easy to install. You might also want to install a Firefox extension called SwitchProxy to let you easily turn the whole apparatus on and off.
Once you've got that up and running, it's as simple as selecting an item from a dropdown to send your web-surfing whizzing through random intermediaries, safely encrypted. Sure, things get slightly slower (slightly). But it's pretty cool to have your homepage pop up with a big "Auf gut Glück!" button: right now, Google thinks I'm in Germany.