I am "the friend" referred to in the questions here and here. I decided to come and ask a question myself, as I can still not connect to the wireless network.

I downloaded Keryx, as suggested here, and managed to download the necessary package and its dependencies. When I attempted to install the packages on Ubuntu using Keryx, Keryx just closed. Following this, I installed the packages manually using dpkg, and as far as I can tell, this was successful:

kieran@ubuntu:~$ cd /host/wifi/Keryx/keryx/projects/Kieran/packages
kieran@ubuntu:/host/wifi/Keryx/keryx/projects/Kieran/packages$ sudo dpkg -i *.deb
[sudo] password for kieran: 
Selecting previously deselected package bcmwl-kernel-source.
(Reading database ... 118296 files and directories currently installed.)
Unpacking bcmwl-kernel-source (from bcmwl-kernel-source_5.60.48.36+bdcom-0ubuntu5_i386.deb) ...
Selecting previously deselected package dkms.
Unpacking dkms (from dkms_2.1.1.2-3ubuntu1.1_all.deb) ...
Selecting previously deselected package fakeroot.
Unpacking fakeroot (from fakeroot_1.14.4-1ubuntu1_i386.deb) ...
Selecting previously deselected package linux-image.
Unpacking linux-image (from linux-image_2.6.35.22.23_i386.deb) ...
Selecting previously deselected package menu.
Unpacking menu (from menu_2.1.44ubuntu1_i386.deb) ...
Selecting previously deselected package patch.
Unpacking patch (from patch_2.6-2ubuntu1_i386.deb) ...
Setting up fakeroot (1.14.4-1ubuntu1) ...
update-alternatives: using /usr/bin/fakeroot-sysv to provide /usr/bin/fakeroot (fakeroot) in auto mode.
Setting up linux-image (2.6.35.22.23) ...
Setting up menu (2.1.44ubuntu1) ...
Setting up patch (2.6-2ubuntu1) ...
Processing triggers for man-db ...
Setting up dkms (2.1.1.2-3ubuntu1.1) ...
Setting up bcmwl-kernel-source (5.60.48.36+bdcom-0ubuntu5) ...
Loading new bcmwl-5.60.48.36+bdcom DKMS files...
First Installation: checking all kernels...
Building only for 2.6.35-22-generic
Building for architecture i686
Building initial module for 2.6.35-22-generic
Done.

wl.ko:
Running module version sanity check.
- Original module
- No original module exists within this kernel
- Installation
- Installing to /lib/modules/2.6.35-22-generic/updates/dkms/
depmod.....
DKMS: install Completed.
update-initramfs: deferring update (trigger activated)
Processing triggers for install-info ...
Processing triggers for doc-base ...
Processing 31 changed 1 added doc-base file(s)...
Registering documents with scrollkeeper...
Processing triggers for menu ...
Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-2.6.35-22-generic
Warning: No support for locale: en_GB.utf8

After rebooting, however, there were still no wireless networks in the NetworkManager Applet list. I opened the file /var/lib/NetworkManager/NetworkManager.state, and both NetworkEnabled and WirelessEnabled were set to True.

While i'm very concious I may be asking a stupid question here, both my friend and I have nothing left to suggest, and as such - I would be very grateful for any answers as to how to get wireless working.