As I'm running Natty Narwhal I used this from and it updated the firmware, installed the driver and started and found my Orange Livebox straight away. Works better than my XP connection too!!

Since Ubuntu 11.04 Natty Narwhal additional installation of the package firmware-b43-installer can be helpful and/or necessary, respectively:
~$ sudo apt-get install b43-fwcutter firmware-b43-installeror, if you need a legacy driver, use:
~$ sudo apt-get install firmware-b43legacy-installer