You could say the original Sidekick was the first shot fired in the smartphone revolution.

With a flip of the thumb, you could expose the physical keyboard hidden behind the screen. It was aligned horizontally to make typing easier, but it wasn’t too bulky. And the large screen — bigger than most other phones in 2002 — made tasks like browsing the web and writing e-mails on your phone actually seem like ideas worth getting used to.

Over the years, the Sidekick and its successors ended up losing out to the newer breed of smartphones ushered in by the iPhone — devices with advanced operating s...