In anticipation of taking some of the courses from offensivesecurty, (thanks to my boss's Credit card) :P
I bought a netbook to use as a dedicated backtrack machine.
I also used one of our servers at the office to run backtrack for speeding up cracking passwords (16gb ram 4 dual core xeon proccessors, raid 10 array of 8 hard drives,) and setup about 5 different boxes on a lab network with two test AP's (one wep, one WPA) Oh do I love it when My boss lets me play at work

Anyway, I bought a laptop from a friend, the Toshiba NB305.
I was delighted to find out that it boots from the SD slot and that the wifi card in it supports packet injection out of the box!
It also gets about 5-8 hours on one battery charge, Icing on the cake.
I maxed out the ram at a measly 2gb (the only downside of the laptop other than the 1024X600 resolution that I would prefer to be higher)
and I will be springing for a new 64GB SSD for it next paycheck...

In case someone else is looking to do something similar, I just wanted to let you know this is a great setup for that purpose, and fairly cheap, I have seen them for 200ish online.

Maybe we can compare other systems out there, If there is something better, let me know. I would be interested to see something in the same price range that can support more ram to do the same thing.

I have used the Acer aspire one in the past(packet injection seemed slow), the Asus EEEPC (701)(Tiny, bad battery life, Keyboard too small) and my Lenovo X201 and all of them work ok for this (with the exception of the video issues I had with my X201, fixed now tho)

Anyone have a better Setup?
An suggestions on how to improve this setup?