What about this scenario?

I am returning my 3G 3.1 phone do to lock ups and dropped signal issues. I will try to get a 3.0 phone.

If I do, what is the first thing to do? Connect to iTunes or Jailbreak/Unlock? I want to use this new phone with T-Mobile, not my ATT number. I do have an account with ATT now.

I want to make sure that I don't screw this up. I already messed up by updating to 3.1 via iTunes before.

What are the steps in order that I should do?

Thanks!

It didn't work. My new phone is 3.1 as well. They don't have any 3.0 phones at all in town.

Will I ever be able to use this 3.1 phone on T-Mobile?

Please, don't double post. Thanks. Thread closed.