I remember seeing a preview of this sometime last year, but a public build is now finally available.
Deepfish is a new type of mobile information browsing experience, aimed at preserving the rich layout and full form of documents on mobile devices while providing novel ways of effectively navigating that content on small screens. Deepfish's unique interface enables you to zoom in and out of page, quickly getting to the areas you are interested in without screen length after screen length of scrolling. And because the layout is preserved, navigation menus, lists of search results or news headlines, and other elements that might have been bent so thoroughly to fit the usual single column layout that they were no longer legible can now be browsed simply and easily. A consequence of Deepfish's multi-resolution approach to browsing pages is that it loads a thumbnail of pages initially and then only what is needed for more detail when requested or in the background as you browse the initial the view, resulting in substantially quicker load times for most pages.http://labs.live.com/Deepfish/default.aspx