Sonar Ruler

Check out this *very* cool utility available now in the iTunes App Store. Sonar Ruler uses sound waves to measure the distance to a solid object (like a wall) and returns it to the iPhone in a visual display.

It's a little tricky at first, but surprisingly accurate! As the app itself says, watch the video below to see how it works, then pop over to the App Store to pick up Sonar Ruler for only $0.99.