Made a little light bar for under my monitor!
4 white leds - 7000 mcd, 3.3V @ 25mA
4 100 ohm resistors (can go as low as around 70 ohms for this project, but I didn't want to be blind).
I cut a corner piece off of a rubbermaid lid, drilled holes, slid in the 5mm LED's, wired everything up in parallel and volia! You have a hacked up, hidden, led bar
Whole project cost was around $6... already had the lid. Next time, I'll use something pretty... like an acrylic rectangle box or something...