I'm pretty sure you can just download the visual styles from there and not have to sign up for anything, or at least you used to be able to.
If not, just apply the uxtheme.dll patch from Neowin (hopefully you've done this by now already) and get your visual styles from DeviantArt, they have a pretty good selection.
These are some of the different visual styles I've used and made screenshots of.
One of the first I used. OSX-like theme.

Very popular and clean style called Luna Element 5.

Get it here:
http://www.deviantart.com/deviation/29511577/Nope, not Vista. Style called
VistaCG.

Logon screen I used to use.