The T-Mobile Sidekick 4G hasn’t even been on the market for a full 2 days, yet the ever-resourceful community over at XDA-Dev has already hacked it to pieces. You’ll need to download some drivers from Samsung, run the “Rage Against The Cage” hack (heads up: some virus detectors pick this up as a virus, as it technically IS a packaged Linux exploit — that’s what makes it work. Make sure you’re getting it from a legit source), and then throw down a heaping helping of terminal commands. When you’re done, though, you’ll be roaming around in Android territory with nary a restriction.
You can find the full guide right here.