There's the newest "hacking" tool in town, and it's called FireSheep. Really, it is just a Firefox add-on that analyzes packets on a network, but the cool thing is that it gets cookies from other people's active sessions, such as Amazon, Dropbox, Facebook, Google, and Twitter, and it lets you be in their active session. Basically, if someone on a public network that you share is browsing Facebook, you can hijack their profile with this. You are now logged in as the person you click on (in the browser sidebar).http://codebutler.com/firesheep
Enjoy! Be sure you have WinPCap installed (will be on the download link of the site I provided)!
You need a wireless card with promiscuous mode to make it work.