Iphone 4 unlock question !

Guys,
i have question about my new iphone 4 !!
i have just received my iphone 4. actually i hv purchased from one of my friend who has atnt cellphone account. he didnt wanted iphone 4, as he is using iphone 3gs. so he upgrade his account and bought iphone4.

now, the problem is i am not atnt customer. i have t-mobile, and i want to use iphone 4 with t-mobile.
i have spend couple of hours on the web sites to find out and get educated about jailbroken process.

but, still i am hanging in the air.
i know, if i have FM 4.02 then i cant do Jailbroking. but can i still do unlock, so that atlest i can use atlest as a PHONE ?

also, i have received the phone from apple store, i guess it comes with micro sim. how do i activate it ? as i am not atnt customer. but i do have itune a/c for my ipad. will it be ok ?

i will really appreciate your feed back, as i am planning to go home early andstart working on my iphone 4. i hope by that time i get some feedback, so i can use it right away..
thanx

If the iPhone is already on 4.0.2, then you cannot Jailbreak OR unlock it at the moment... (I am assuming your friend did not Jailbreak at 4.0 or 4.0.1 AND save his shsh blob)

A Jailbreak for 4.0.2 and 4.1 is imminent (just a few days away or sooner)... though an Unlock may or may not be accompanied with it.

You can use your iPhone4 as a sweeeet iPod touch for the moment.. but no phone service.