by Mike Krumboltz It hasn't gotten the press of the "Retina Display" or "Facetime," but the iPhone 4's tethering capabilities are nothing to sneeze at. Tethering, for those who don't know, allows a person to use their cell phone's signal to get their Wi-Fi enabled laptops online. It's pretty cool. Unfortunately, it isn't free. AT&T wants $20 a month for the feature. But a 15-year-old named Nick Lee found a way around the fee. Lee created an app, called "Handy Light,