Mechanical keyboards have become rather common, though mechanical keys that are also individually backlit are comparatively rare. True, you're paying for that combination, but it's certainly worth it if you game or type in low-light environments.
The Rosewill Rk-9100's individually backlit keys are illuminated in a lovely shade of azure blue, saving the caps and num lock keys, which shine emerald green. F11 and F12 adjust the brightness between four different levels; F9 switches modes, with either the whole board, everything but the number pad, or just the WASD and number keys lit up; and F10 turns the illumination on and off entirely.
In any light scenario, the RK-9100 is a gorgeous specimen. When it lights up for the first time and bathes you in its glow, you'll see it too.
I've got a few criticisms, though: even at the lowest settings, the RK-9100 is extremely bright. Further, the caps and num lock keys, with their separate, green lights, have only one setting: really bright. And the lighting around some keys, like the function keys, is a little uneven, though that's a nitpick for sure.