Environment:

• Ubuntu 12.04.3 LTS
• Linux kernel 3.2.0-52-generic-pae
• Alfa 802.11a/b/g/n long-range USB adapter (AWUS051NH)
• Kismet 2013-03-R0

The instructions provided here here were helpful, and I used them as a rough guideline for getting things working.

Here's the driver for the 2.4/2.6 kernels (the link in the page above is stale -- it looks like companies have merged).

Use this patch to get the driver to compile on Linux 3.2 kernels. (It's a hack -- I don't know if there are other subtle changes or not, but at least it compiles and seems to run with it; the USB antenna doesn't seem to be as sensitive, however.)

What I did:

1. Downloaded the driver, unpacked it, and applied the patch
2. ran 'make' (the Makefile settings were already correct)
3. ran 'make install' (install the kernel module)
4. ran 'depmod -a'
5. (I did a reboot here on general principles -- I had been messing with settings for a while)
6. Plugged in the Alfa WiFi USB adapter
7. Voila! It worked!

At this point, the following Alfa-specific modules were loaded:

• rt2870sta
• rt2800usb
• rt2800lib
• rt2x00usb
• rt2x00lib

For kismet, the ONLY module that seems to be necessary is 'rt2870sta', but the blinky light on the adapter won't illuminate unless the other four (or some combination of them) modules are also loaded.

Note: I didn't try to do anything with the supplicant or configuring that; I was only interested in wireless monitoring, not connecting to APs.