The Beanstalk guys are starting to expand into the design arena with their latest feature announcement for Design Preview.
The idea reminds me a lot of the 2-up or 4-up view in the Save for Web dialog in Photoshop, except instead of comparing compression levels, you are comparing previous versions of the document. What makes this ridiculously useful is that it works on both images and HTML documents — yes, CSS and images are pulled into a real HTML preview.
As expected, you can view the documents side-by-side as well as overlaid on top of one another. You can even make the document public to share with clients.
Personally, I’d love to see this idea expand into a larger preview browsing tool, ready for client consumption. Seriously, how many times have you wished for a more automated solution to sharing various design options to clients (options, not versions)? You could technically hack it by overwriting the preview file a few times, but who wants to do that?
Check it: Beanstalk: Version Control for Designers.