So I was chatting with a Microsoft friend of mine today. He's a Firephox fanboi. He's always trying to convert me. He was talking to me about FF 3.0's pending release and talking about how amazingly fast it is on his XP SP3 rig. So I started admonishing him for running such an archaic OS and he of course shot back that he only runs it on his older hardware that isn't really suitable for Vista. Okay - fair enough . . . but then I mention that I will never run Firefox on Vista because it runs at Medium IL and my IE7 browser runs at Low IL . . . which makes me feel safer since shellcode and malware running at low IL can't really write anywhere interesting to persist a logoff / restart / closing the browser etc.
Anyhoo - during this chat he mentioned that on his XP SP3 machine he uses Windows SteadyState . . . on his 'extra' older / legacy PC he installed this software and surfs the web using Firefox on XP SP3 . . . if he ever questions the security of his system - he just shuts it down and undoes all of the changes and then restarts - sort of like shutting down a virtual machine and discarding all the changes using an undo disk. He mentioned that when guests come over they can use 'that' PC to surf the web and then when they leave he can just undo all the changes.
I have to admit - it's a pretty damned good idea . . . it's a free download, it runs on XP, it runs on Vista and it allows you to roll back any badness . . . it also provides easy ways to patch itself (it can be configured to auto-patch or you can login and do it yourself which seems the better route).