Update: There are reports that the Razer doesn't really use OLED keys. The keyboard is actually a touch LCD (one 7" LCD) with transparent keys on top. Clever design!
Razer has a nice small laptop on display at CES, with an OLED keyboard. The idea is similar to Art Lebedev's OLED Optimus (which interestingly is still available for $2400) - each key is a small OLED: