Im about to buy an IPhone this weekend and was wondering something.

1) Unlocking the phone would only be necessary if I was wanting to use the phone if Im not with AT&T correct? I stiil want to use AT&T as my carrier cause I will be signing a 2yr contract.

2) I was just wanting to mod the phone in term as of adding apps and customizing themes and ringtones etc. etc. So should I just jailbreak it? Thats what jailbreaking it essentially allows you to do right?

3) Should I jailbreak before I activate or activate then jailbreak or does it really matter? This will be a new Iphone so prolly be running on 1.1.2