If you are looking for a WiFI USB adapter which works out of the box in Fedora or Linux, it is worth to try LM Technologies WiFi USB Adapter.
My friend bought this one from Amazon.co.uk for only 7 pound:
To see whether it works, he tested on my Fedora 13 laptop though I mentioned that it probably would not work due to the lack of Linux driver. Amazingly, it works just as it should be without any configuration. NetworkManager recognise it in second.
Here is the dmesg information about this usb wireless dongle.
usb 2-4: new high speed USB device using ehci_hcd and address 5
usb 2-4: New USB device found, idVendor=0ace, idProduct=1215
usb 2-4: New USB device strings: Mfr=16, Product=32, SerialNumber=0
usb 2-4: Product: USB2.0 WLAN
usb 2-4: Manufacturer: ZyDAS
usb 2-4: reset high speed USB device using ehci_hcd and address 5
phy1: Selected rate control algorithm 'minstrel'
zd1211rw 2-4:1.0: phy1
usbcore: registered new interface driver zd1211rw
usb 2-4: firmware: requesting zd1211/zd1211b_ub
usb 2-4: firmware: requesting zd1211/zd1211b_uphr
zd1211rw 2-4:1.0: firmware version 4725
zd1211rw 2-4:1.0: zd1211b chip 0ace:1215 v4810 high 00-02-72 AL2230_RF pa0 g--NS
cfg80211: Calling CRDA for country: DE
cfg80211: Current regulatory domain intersected:
(start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
(2402000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm)
(5170000 KHz - 5250000 KHz @ 40000 KHz), (N/A, 2000 mBm)
(5250000 KHz - 5330000 KHz @ 40000 KHz), (N/A, 2000 mBm)
(5490000 KHz - 5710000 KHz @ 40000 KHz), (N/A, 2698 mBm)
ADDRCONF(NETDEV_UP): wlan1: link is not ready