Nevermind about the namespace. I got that from the samples. 

Also, it looks like you can't really select multiple files for upload, but rather you can upload a bunch of files sequentially, which really isn't the same thing.

Thanks.

Aaron Edwards:

This is the demo of uploading multiple files, c# ASP.NET AJAX.  I don't see anything, either in the Choose File dialog, or in the main window, to allow you to select more than one file.  Am I missing something?  Am I just really dumb?  I tried shift-clicking, and control-clickng, but that didn't work.  I tried IE7 and the current version of FireFox, 2.0.0.16.

Also, while I'm at it, what is the namespace  that the Uploader, UploaderEventArgs etc. classes live in?  Thanks!