I’ve never seen the point in adding internal lighting to your PC but if you’re that way inclined you can now do it really easily with the LED Flash Power Y Cable.

The LED Flash Power Y Cable acts as a two way adapter for the standard power connectors found inside your PC but all 3 ends also incorporate bright blue or red lights, making your PC internals glow. Probably not suited to the typical beige PC but if you have a flash case and want to make the most of that glass window then why not.

Available from Think Geek for 7 bucks.