If you have a wireless card try airodump, aireplay, and aircrack.. I use it to test and secure my home network..
Unfortunately, I'm running off either one of the desktops on campus or at my folks' home. And they're somewhat squeamish anytime they ask me what I do on the computer and I tell them I'm using OSS and/or Linux ;)
As for my laptop, I had to turn it back to the university when I transferred. Real nice computer (HP Compaq nc6000), but no buyback option was available.
But if I get a laptop again and I'm able to set up my own small network, I'll definitely try it.