Okay, so I've got my Eee PC 900 which is currently kitted out with Ubuntu 9.10.
And then I added Aircrack-ng:
sudo apt-get install aircrack-ng
And it was good.
But it got better when I downloaded a GUI for it from here, extracted it to my home folder and...

...now I have no need of Backtrack!
I should also point out that this worked on my brother's 701 4GB and my other brother's 1005HA.
Um, and that's it. Short and to the point.