If you're in the market for a solid USB microphone, you should definitely check out Blue Microphones' Spark Digital. Not only is this a USB microphone, but it will also work with any iOS device that has a Lightning port. Check out the video review above for a complete overview and audio test.
Blue has been around making high end microphones for ages. They recently got into the iOS business making some pretty awesome mics for iOS devices. The newest addition to the Blue line is going to be Mikey Digital and Spark ...