The Optimus Maximus keyboard by Art. Lebedev Studio began shipping this week. This is one of the neatest toys to come out in quite a while. Every single key is an individual LCD screen, therefore, you can endlessly re-configure the keys to meet your needs - perfect for apps like Photoshop or World of Warcraft.
Imagine working on something that requires you to drop in a weird character. You change your font to Wingdings, and your entire keyboard instantly re-maps to show you all of the characters that are represented by each letter. Or, say you're writing something in multiple languages. While it's pretty easy to use special characters on a Mac, Windows users have a hard time. Just press a button and your keyboard changes to a Russian keyboard.
The nerds over at Engadget have a pretty good review with lots and lots of juicy pictures.