theme xp is the one i've heard of too, and I agree with you chris882e. On these free programs, you can't customise much, and end up using themes other people have made, when you wish you could do it yourself, and change every setting you want, including selecting Window looks, and changing how they look. That would be really good.
Like a complete windows changer you could draw using Flash or something and export using gifs or jpegs, that would replace the windows GUI. Is there anything like that?
Because really, explorer is only a mask, so surely theres something like that, because windows is already programmed so when you press a button it opens a seperate program over explorer.exe or opens a menu item...