I actually wanted a Sidekick, but I switched from T-mobile to Alltel when my oldest daughter moved out west. Her plan was cheaper than mine and taking over her old phone number gave her a failsafe for contacts that did not know she was California bound. Alltel didn't offer one, so I went with something different.
Which now in reading the Blade's article this morning about the complete melt down of the data servers, I'm glad I didn't.
This does however point out that you should take the time every now and then to save your contacts, every so often I email all of my phone numbers to myself, that way I'll always have them as a back up.