I take it I cant sync all my music unless its jailbroken?
Hey! You can do exactly the same as you would normally do with an un-jailbroken iPhone but MUCH more. Let me try and explain.
I have jailbroken my 4 and many of my friends iPods 3G's etc and you have different types of reasons for doing it. One reason is so you can unlock the carrier to let any network sim function properly. Two is to get certain apps that are unavailable through the app store (via Cydia: like wifi sync, myfi, 3G unrestrictor and the rest) that make your iPhone even more of a useful tool. And then you get the third type which is the pirate who wants all the apps for free. Once jailbroken you can download any app you want for free and you can also download free music and free films quite easily. I wouldn't advocate the third option as it is classed as illegal but the first two are not.
So don't worry about your phone becoming this flea infested buggy device because it will look and act the same as a normal iPhone. If all goes wrong you use a programme called 'Tiny Umbrella' to reset the firmware and use iTunes to do the rest and it will be back to normal and Apple have no way of finding out what you have been up to.
If you need any help or advice on what to do next I can talk you through it.