A few months back I bought a couple of cheap USB WiFi adapters from DealExtreme. Today I finally got around to try them on the Raspberry Pi. Of the three adapters, two works both on a Fedora 17 64 bits based desktop as well as on the RPi. Notice that they both seem to contain the same chip, and indeed reports the same vendor and product ID. The last, the EDUP device, does detect available WiFi networks, but usually does not establish a connection (the very last time I tried, it suddenly did). I suspect it might be a USB power issue, since it also "crashed" the USB hub on the desktop, causing the keyboard and mouse to temporarily disconnect. Here are some notes which might be related. Of the three, the one with antenna is fastest at establishing the connection, but the other small adapter also gives good transfer speed; around 3.6 Mb/s seen today, but I expect it can go faster.

For other devices supported by the RPi, see the the Embedded Linux WiFi page, and also Element 14's WiFi testing page.

Product Description USB kernel info NetworkManger info Fedora 17 x86_64 Raspbian "wheezy" Comment
USB 2.0 2.4GHz 802.11b/g/n 150Mbps WiFi/WLAN Wireless Network Adapter USB 2.0 2.4GHz 802.11b/g/n 150Mbps WiFi/WLAN Wireless Network Adapter idVendor=148f, idProduct=5370
Product: 802.11 n WLAN
Manufacturer: Ralink
SerialNumber: 1.0
driver: 'rt2800usb' OK OK Works "Plug & Play".
Connection is established quickly.
Mini USB 2.4GHz 150Mbps 802.11b/g/n WiFi Wireless Network Card Adapter - Black Mini USB 2.4GHz 150Mbps 802.11b/g/n WiFi Wireless Network Card Adapter - Black idVendor=148f, idProduct=5370
Product: 802.11 n WLAN
Manufacturer: Ralink
SerialNumber: 1.0
driver: 'rt2800usb' OK OK Works "Plug & Play".
Somewhat slow at establishing the network connection.
Ultra-Mini Nano USB 2.0 802.11n 150Mbps Wifi/WLAN Wireless Network Adapter Ultra-Mini Nano USB 2.0 802.11n 150Mbps Wifi/WLAN Wireless Network Adapter idVendor=0bda, idProduct=8176
Manufacturer: Retek
driver: 'rtl8192cu' Failed.
Hangs USB host.
Failed.
Works 1 out of 10 times. Crashes the RPi.
Device detected, and sees available WiFi networks, hover does usually not get a connection.