Been trying out vLite
, It's looking pretty cool. Basically it allows you to configure Vista before it's even installed. You extract an ISO, customize the features you want in your install, and add extra drivers etc, then recontruct it and burn it. From there you can install your own custom Vista.
I've managed to get my install down to 800mb after stripping out loads of crap and it sure does run sweet :P
I'm going to post some tutorials and instructions etc on my site as soon as I've played with it some more.