For the majority of Ubuntu users you will all have very little to do with having to manually install additional device drivers for integrated wireless cards on laptops.
However there are certain few cases where updated drivers are needed to get full functionality from your wifi hardware.
I recently encountered one such case with a Thinkpad Z61m. It had a newer edition Atheros wifi chipset. I was slightly disappointed that the restricted Atheros driver which comes with Ubuntu, did not work properly. For instance, I could see the wireless networks and if it was not an encrypted on I could connect to it. However, if it was encrypted I could not and there were other problems with switching back and forth from wired to wireless.
So I set about finding a solution and was lucky enough to have a friend in the US who suggested I try installing the latest madwifi package from their site. ( http://madwifi.org )
So I set about doing so. Needless to say it worked!
A How-To has been written. CLICK HERE