I stumbled across this keyboard the other day (I seem to stumble a lot nowadays).

Each key is a tiny screen comprised of Organic Light-Emitting Diodes (OLEDs) which will display, "...different fonts, languages, notes, numerals, special symbols, HTML codes, mathematical functions, or your own customizable images. Using Photoshop, for instance, the keyboard will display special tools such as brushes, layers, and filters; in Microsoft Word, it will show multi-lingual fonts of your choosing, cut, copy, paste, and so on; in games, images showing movement and weapons will be displayed."

It appears that this is going into production and will cost a mere $400

See it here: http://www.artlebedev.com/everything/optimus/
More here: http://community.livejournal.com/optimus_project/