Can I use a Blackberry Sim for a Sidekick or T-Mobile phone, or where can I find a cheap cool phone?

It should work, you will just have to contact T-Mobile and change the "Blackberry" data plan to the Sidekick data plan!  Right now the myTouch 3g is selling for $179.00 with a new contract or upgrade
The phone that keeps you crazy-close to family and friends. Get yours in white, black or red.

• Large 3.4” screen
• Full Qwerty keyboard
• Swype™ keyboard preloaded
• 5 MP Camera
• Thousands of Android Apps



The Sidekick lx 2009 is at $49.99 with new contract or upgrade
Kick it to the next level. The new Sidekick LX is sleeker and slimmer, including a large screen that incorporates high-definition LCD technology, a camera with flash, and mood lights which lets users set specific settings for various communication alerts. The LX is also Bluetooth capable, and has signature swivel screen, amazing keyboard, plus built-in, always on social networking apps you can't miss. A data service is required with this phone