Bringing a smartphone from the US. Would it work in Poland?

I am thinking of purchasing a smartphone in the US to bring with me to Poland because I think it might cost less, but I've heard that the data frequencies are different between Europe and the US. Anybody know what would work? I know I would need a GSM phone but it is important that the data functions work too. I was thinking of getting an HTC phone but I want to know it will work in Europe too.

I think you will get a better deal on an HTC mobile in Europe as a lot of them are released here first and some of them do not even make it to the US market.

I buy my mobiles from the UK through Ebay LINK I think you also need to keep in mind that buying from outside the EU you will be susceptible to import tax as well and that is another good reason to buy in the EU.

Tmobile will work. If verizon you will need a global phone for the different radio, you just buy a sim card in Poland. I had problems with droid 2 global. Voice worked but not data

check the specs, any decent phone should have quadband and GPRS/EDGE/3G data transmission

make sure its not locked to any provider though