Want a USB mini-microphone array. Is it possible?
The Playstation Eye video camera has a 4-element linear microphone array.  It provides 16-bit samples at 48 KHz with a SNR of 90 dB.  It's easy to use: it enumerates as a standard USB audio device with four separate channels.

For an example of using it this way, see: PS3 Eye 4-channel Audio Tests on Ubuntu Karmic