i've been using my ihpone for more the 6 months now and it works great. I love it and never had any problem with it since i unlocked it. it's easy to unlock now BTW.

I even upgrade it every other month just so i can use the new features and i love the 3rd party applications.

If you're not in a hurry there are rumours of a 3G iphone coming out soon so you can profit of a price cut or even get the 3G one. only rumours though.