Continuing the thread of what makes good innovation, let me introduce you to Wikipedia Scanner, which takes IP address information available from Wikipedia for anonymous edits and compares that info with who owns particular IP blocks to discover who is making anonymous edits to one of the world's most popular sites. It's created by Virgil Griffith (well worth reading his Wikipedia entry).
Royalty, the CIA, voting machine maker Diebold and others have all tapped into Wikipedia to change entries related to themselves (or something they are interested in).
I personally think the idea is freaking brilliant. But beyond that, it is a simple but extraordinarily powerful idea. And check out the design. Nothing flashy, it just does the job it's supposed to.
Oh yeah, read Wired.com's list of edits identified so far.