I agree with both post above me about contracts and unlocked phones, but you never know what you'll find. Maybe Tmo will give a special deal if you get the n900 with a plan?

I never thought I'd be in a contract with one of the local operators, but they gave such a good deal that it was hard to refuse:

3000min
3000 txt msgs
unlimited internet, and the coverage is pretty good with about 95% of places I go have 3.5G.
and you get the Nokia N900, for 57€/month for 2 years.

I know the annoyance of being in a contract, but never say never =)

gl guys...