Looking for sites that have different 'skins'

I am researching a project that I am doing the design work for.

Basically it involves using a variety of different website layouts, which can then have adjusted colours, but have the same information in each design.

Basicallys o the user can pick a wesite layout, and colourscheme that suits them best.

Does anyone have any links to good site that changes skin quite drasically or subtly to give me some inspiration?

Thanks