I downloaded a new free application called Zumobi tonight and like the overall concept.  It's a bit slow on my phone (PPC-6700) but useable.  The application lets you pick up to 16 tiles (mini applications) that can be displayed on your phone and then lets you zoom into 4 tiles and then down to 1 tile.  For example, you can have sports tiles, amazon.com tiles, Woot tiles, game tiles, etc. and then navigate the tiles and drill down into them to view details (such as sports news, the latest item on Woot.com, etc.).  It has some iPhone-like zoom animations which are good compared to typical applications that run on Windows Mobile phones. 

Here's what it looks like:

They have a gallery of tiles that can be selected and sent to your phone plus you can download an SDK to develop your own tiles.

I've only played with it for a little bit but so far I'm impressed with the concept.  As more and more tiles are made available it should be a great way to view content on a Windows Mobile phone.