Switching to BB, HELP!!

This might be a stupid question, and probably been covered on the forum, but i can't seem to find it....

I currently have an iphone, and i am considering getting a BB curve 8900 in the near future. A person contacted me saying he wanted to trade my 3mo old iphone 3g for his brand new, in the box, t-mobile bb curve 8900.

*** i was wondering what i would need to know about an exchange like this, if i wanted to trade for the t-mobile phone and use it with my ATT contract.
(ex. unlocking, compatibility, anything lost in exchange?)***

Also, maybe perhaps share some highlights i can look forward to with a bb over my current iphone.

You can always find a person who wants to trade for an AT&T Curve 8900 that way you don't have to worry about unlocking it.

You may also want to make sure the PIN on the blackberry is not attached to any accounts that way you can add it to yours...

what do you mean attached to any accounts?

Call ATT with the MEID of the phone, found under the batter, and ensure the phone isn't stolen.