Zumobi is a zooming interface & mobile widget platform for mobile devices.  I tested it out on my AT&T Tilt and was underwhelmed.  My user experience can be summed up in three words: bloated, slow, & buggy.  Oh, and it was a resource hog and did I mention slow, man was it slow.  You would think from all the demo videos that you’d be able to zoom around, but that just wasn’t happening. 

Now it could be that I had a unique experience, but I did see via scobleizer.com’s shared items that Russell Beattie wrote a scathing review of Zumobi that is far better than any thing I could come up with.

My advice: Stay away.  At least until it is out of beta.