Not true. Jailbreaking and unlocking are two different things.
Jailbreaking allows added functionality, including installing apps from places other than the itunes store, changing the standard message tones, tethering without having to pay O2 £15 per month. All the things a good phone does as standard. (I do own an Iphone by the way).
Jailbreaking is not illegal, although Apple might like you to think so.
how is it possible to get it done, and where would i be able to download the other apps from if i get my phone jailbreaked, as when ever i search for iphone apps what ever i dwnload it always go via itunes.
what you mean by teathering aswel, im on orange i that makes any differeance to it
It's not illegal and it doesn't unblock your iPhone to any network. As stated above it's just different software to make the phone better/on par with normal phones. Just back up your phone on iTunes first then f anything goes wrong or you need to give the phone in to apple for any reason go back to the backup. Never done it personally, been using my iPhone for 14 months as standard and I find it fine. Might have a go soon just to find out what's so great about it, contract is nearly up anyways so may aswell!