If you can save a page look, why not share it with other users? Let people share their setups like themes.
That's so important I'm going to say it again. Let people share their layouts.
Like the Stylebot page said, that's what the C in CSS is all about. It's just never caught on much. (In reality, this is largely due to the structural layout of many sites not being amenable to any CSS other than the sheets crafted by the original "designer".)