I recently started contributing to the wikispeedia database and I've become very optimistic about the future of this project. While the theme of this particular app is humorous, it serves a very important purpose. Crowd-sourcing for accurate location-specific speed limit tracking. Imagine never looking for a speed limit sign again, and simply knowing the limit from your mobile phone or integrated device, and whether you're obeying this limit or not. On another note, it has been found to be valid evidence in a court of law if one can present GPS-based speed data at the time of a speeding ticket.