Sprint has just revealed an ace up its sleeve: the Overdrive, a 4G mobile hotspot. Sprint is the first in the US to offer 4G internet connectivity that is rated at 6Mbps for downloads. By combining the speedy cellular connectivity with a mobile hotspot that generates WiFi signals Sprint has up-ended the market. You can use your iPhone or any WiFi-capable smartphone or mobile device to connect anywhere at 4G speeds. Apple’s iPhone 4G better have much more than just faster speeds when it launches. And there does not seem to be any reason why you should spend more money on a 3G iPad. Of course, there is a caveat: only 25 markets are served 4G. Find out whether you’re in one of those markets or not and watch the quaint ad on YouTube.