I had to see what all the fuss was about. I have a iPhone 4 and use the latest ios 6. The new update is not the greatest, but that is another story. I followed this excellent tutorial by idownloadblog. Remember that if you try to jailbreak your iphone take it slow and always backup your device before using itunes. That way you can always restore your phone later if you don’t like the jailbreak.
You are going to have to install Cydia as well which is basically the app store for jailbroken iPhones. It is not as intuitive and takes much more time getting used to. I would set aside a weekend day if you are going to try to set all this up. Overall I can see the appeal of jailbreaking, but it is very time consuming and you have to have the real drive for technology to make use out of it. Also I noticed that apps are unstable and cause quite a few crashes.
Since IOS 6 is still relatively new there is only a tethered jailbreak out. This means that if you power down your phone or it runs out of batteries, then you have to reboot the phone.
Instead of writing down cool functions that you can do once you have your phone jailbroken, I found this cool video that shows some of them.