I've been playing around with Backtrack 5 recently, and I've discovered something very interesting in a short amount of time: It's very powerful!!
Junior here guys on a very quick thought.
After exploring the deep regions of this linux OS, all I have is: WOW. If used in the wrong hands, this can get you into some serious trouble. However it can also be extremely helpful (I think) to see just how secure your networks are. I've been doing that with my personal network, and so far I've been able to make advancements. Minor adjustments of course. I do find it interesting upon first boot, you see it loads Ubuntu 10. THEN into BT5. Weird!!
It IS a free download. Kids, use this OS appropriately and responsibly. I'm not going into detail on what this OS can do (hopefully for resons a bit of Google'ing can solve), but just use it responsibly.