Since I installed Ubnutu 7.0.4, I lost my wireless connectivity and had to stay in my bedroom where my network hub is installed. I had been trying to get it working but was not successful.
I came across Sam Liu's blog about installing the wireless adapter which is a step by step tutorial to install the driver.
It uses ndiswrapper and prism02 driver from windows.
If I remember correctly, earlier I followed his steps but didn't work and that was because I didn't follow his steps to reboot the laptop. So follow his steps and have wireless access to net !!