I just got a new cell phone: The T-Mobile Sidekick ID. This is re-branded version of the Danger Hiptop. I got the "light" version of the Sidekick III that does not come with bluetooth or a camera.
Overall, I am very happy with my Sidekick. It has many features that I've never had in a handheld device before. Many of the limitations that I have found are compared to a full featured desktop with a wired internet connection.