Blue Microphones Snowball - High Quality USB Microphone - Brushed Alum.

Finally, a USB mic that's not only easy to use, but sounds as good on your desktop as it does in a professional recording studio. Meet the Snowball; the world's first professional USB mic.

Whether you're recording a guitar at your kitchen table or a complete band in the studio, the Snowball can capture it with detail unheard of before in a USB mic.

System Requirements
Windows: Vista or XP; USB 1.0 or 2.0; 64MB RAM (minimum)
Macintosh: Mac OSX; USB 1.0 or 2.0; 64MB RAM (minimum)