If you're familiar with Android apps like CellFinder, you've got a good idea for what this is -- and the name "Signal" is a pretty accurate representation, too. Basically, iPhone Dev Team member planetbeing has thrown together a neat little app that shows you signal strengths of your phone's connections to nearby cell towers along with their position relative to you (if the positions can be determined), an especially welcome utility considering that you can't access Apple's old "field test mode" in iOS 4. Our favorite part, though, has to be planetbeing's desire to turn this from mere information into entertainment -- and to hopefully take the edge off your pain and deep-set resentment over the signal strength and call dropping issues in your iPhone 4 -- by adding a mode where your goal is to get the signal to drop completely, at which point you'll hear the voice of Spock announce a Vulcan death grip. Who knew an engineering defect could be so much fun? If you're jailbroken -- or you're willing to jailbreak -- you can score Signal in Cydia for a five-spot. Follow the break for video of the app in action.