I just stumbled across this Microsoft Labs site that allows you to try out DeepZoom using your own photos.
For some reason they’re using the PhotoZoom name with an abomination of a logo, but look past that, it’s sure to change before final release of this product.
Sign-in using your Live ID, enter a username, then add your own albums and upload your photos.
Remember you’ll be zooming in on these pics, so upload the highest quality available.
The process isn’t fast, especially when it creates the zooming information, but be patient, the result is worth it.
Here’s my test using photos from my recent Sydney trip. (requires Silverlight 2)
Check it out @ http://photozoom.mslivelabs.com