Ubiquiti Networks SR71-USB abgn USB Wireless Adapter
http://www.wikidevi.com/files/images/sr71-usb.jpg
Chipset: Atheros AR9001U-2NX (AR9170 + AR9104)
Antenna connectors: 2x MMCX
Datasheet
Windows driver

This is just the dongle. No antennas, accessories, or CDs are included. You will need an antenna if you want to use the device.

The devices are supported in Linux by carl9170, written by the most highly esteemed Christian Lamparter. The driver makes use of the highly irregular attribute of an open firmware (Atheros GPLed the firmware back in 2009). carl9170 supports station (a/b/g/[draft-]-n), ad-hoc, AP, and monitor (w/ injection) modes.

The devices will work with AirMagnet in Windows.

The total price shipped is the equivalent of 23 USD converted to BTC as the highest current MtGox bid. Multiple adapters will be cheaper as shipping can be combined.

If you are interested in MMCX (m) -> RP-SMA (f) pigtails, I have a limited quantity and can include them at the price of 10 USD for each. If there is significant demand (LOL!), I can look into acquiring more (and perhaps other types).