I recently acquired a Raspberry Pi, and have installed Debian Squeeze on it, and after doing a small bit of research (I'm not too proficient with Linux) I found and ordered a USB wireless dongle (LevelOne WUA-0605 N_Max Wireless USB Adapter) that appears to have support for Linux. This is the page I found that looks like it says the dongle has a Linux driver. I installed (what I think) was the driver package, firmware-ralink. Now I'm not sure what i need to do to make it work.  lsusb lists the device asBus 001 Device 008: ID 0bda:8172 Realtek Semiconductor Corp.    RTL8191SU 802.11n wLAN Adapter
Raspberry Pi Wireless USB stick
drivers;usb;wifi;raspberry pi
Your problem may be that the Raspberry-Pi uses an arm cpu whereas most linux computers use intel/amd.Hereon the Raspberry-Pi wiki there is a list of tested usb wifi dongles. If you cannot get yours to work or cannot get the correct driver then you may consider buying one of these.If you have a model b and can connect your pi to the internet try sudo apt-get install firmware-ralink If you cannot get it to work then the pi forums would be a better place to ask for help because they will give you more specialized answers.Good Luck.