x-micro Wireless USB (zd1201 chipset)
I got it to work very easily, on Mandrak 2006, should work on any other distro.
First, download the latest firmware and unpack it to (example) \home\user\temp
open command shell.
enter su (superuser) press enter
enter your password for root
The firmware/driver is now installed to correct path.
Remove X-micro wireless USB and plug back in again.
Open network control panel, select add new network/device, select wireless, select WLAN device (it may even display the same name of you other onboard PCI cards). I have a 3com PCMCIA NIC, it showed the eth0:3com nic and WLAN:3com... so I chose WLAN 3com.
U might then get asked to enter your wireless networks SSID (the name you gave your wireless network on your router's control page) and the WEP key (if any).
Then select the type of WEP network type (open/shared, etc), if any.
Go to Finish
On your desktop next to time you might see 2 disconnected plugs, right click, select your wireless network. You might now get a window showing your networks, click connect. On the network status, there should be a button "Thernet connect". click this. you should now see bytes received/transferred on the wireless network.
Your connected and can surf.
I almost gave up in frustration, as my use of linux would've depended on getting wireless connection going.
BTW, this was how I got this card working on Mandrake 2006. Otjher distros might be different.