When installing Ubuntu (at least up till 10.10) you will not get wireless working out of the box unless you plugin a cable.

This is fairly annoying! Fortunately there is a way around this limitation. 

After installing the Ubuntu it self you plug in the usb key after the first boot. Get to know the mount point of the usb key:

<code> 
tdd@tdd-probook:~$ mount
/dev/sda6 on / type ext4 (rw,errors=remount-ro,commit=600)
proc on /proc type proc (rw,noexec,nosuid,nodev)
none on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /dev type devtmpfs (rw,mode=0755)
none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
none on /dev/shm type tmpfs (rw,nosuid,nodev)
none on /var/run type tmpfs (rw,nosuid,mode=0755)
none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
none on /var/lib/ureadahead/debugfs type debugfs (rw,relatime)
none on /proc/fs/vmblock/mountPoint type vmblock (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
/dev/sdb1 on /media/512B-F817 type vfat (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush)
</code>

From the last line we now know the mount point is: /media/512B-F817

Now enter the sources.list file:
<code>
sudo vi /etc/apt/sources.list
</code>

Insert this at the end:
<file>
deb file:/media/512B-F817 maverick main restricted
</file>

Save the file and update apt:

<code>
sudo apt-get update
</code>

It will through a lot of errors at you but that is okay as we don't have a network connection at the moment.

Next up is the installation of the Broadcom driver and building environment. Again in the shell type:

<code>
sudo apt-get install bcmwl-kernel-sources -y
</code>

This will install the needed software to get it going. Go into the "Additional Drivers" application and verify that the driver is activated. When that is done reboot the machine.

When the machine is back up you will have a working wireless network.