Cingular made a deal with MySpace.
I heard a few people having problems browsing though MySpace using a mobile phone other than Cingular.
So if you going to do lots of browsing on MySpace, get Cingular.
You should know that if you browse MySpace alot on the PC. There's several ads for Cingular.
If for some reason you can not get Cingular because of the contract with T-mobile, I will say choose a different cell phone besides Sidekick 3.
Check out my comparison chart for all the smart phones by T-mobile.
http://www.geocites.com/sk3vsbb8100/
But if you have to have the Sidekick, than get the Sidekick 3. They made several improvements on web browsing. You will have problems browsing the Internet using Sidekick 2.