T-Mobile just announced yesterday the new Sidekick (2008) with custom shells. Here is also one of the first Sidekick 2008 review. Our review partner tested the still available Sidekick LX.

Quote from the review: "The Sidekick LX is an upgrade to the Sidekick 3, with a vastly improved screen, slimmer profile, video support, and a standard headphone jack. The flip-out screen and roomy QWERTY keyboard are the centerpieces, ensuring that kids will be hammering out messages instead of paying attention to where they're going for some time to come. Prospective iPhone buyers will be disappointed by the Sidekick LX's lack of robust 3rd-party app support and WiFi. But make no mistake: You can't beat the LX for compulsive texters and instant-messaging nuts."
Read the full Sidekick LX Review.