Just a quick side note: if you are thinking about trying to jailbreak your phone on your own, you need to know that it is quite risky. My sister-in-law tried it, and found out the hard way what bricking means! If you are unfamiliar with the term, bricking your iPhone means that you have made it completely useless like a brick! My sister-in-law lost all of her apps, all of her contacts, everything! I have a sneaky suspicion that next time she will use the software I recommend here! Anyway, the point here is that you can do it yourself, but I wouldnt recommend it because it is highly uncertain. It is definitely not worth having to buy a new phone.
The programs I will list below will jailbreak your iPhone in a matter of minutes, which is another advantage of using the software instead of trying to do it yourself; minutes versus hours. You can do it in just a couple of steps, plus you have technical support to guide you, instead of making an educated guess. Personally, I like the idea of having someone to fall back on in case I make a mistake. So, without further delay, here are my top picks (in order from favorite to least favorite):
