I've posted my live samples from the ASP.NET conferences to play with and crash my server <g>. You can play with them here:

http://www.west-wind.com/presentations/scriptcallbacks/sample/

I'll post the actual samples later in the week. Ah what the hell, here's the link:

www.west-wind.com/presentations/introtoajax/introtoajax.zip

There's a bunch of different demos, some interesting, some more geared towards demonstrating the technology rather than being practical.

In the latter category is the Anthem.NET chat sample, which is kinda fun, but a rather good example of the kind of thing you shouldn't do with AJAX because – well there are much better ways to do this like say, uhm IRC.  Actually, I did the chat sample for a couple of reasons – it demonstrates Anthems control functionality really nicely, but it also demonstrates issues to watch out for such as sending too much data back and forth due to the control posting back viewstate and content on each hit.

There's also an ATLAS Stock portfolio demo that is kinda cool. It works well, but it uses Office Web Components for the graphing portion of it and OWC is sucking the life out of the startup times for the app. The app takes 30 seconds + to start up and taking out the OWC reference makes it come up in 5 or less. Not sure what that's all about - I have to mess around with that some more.

The problem here is that OWC is referenced through the GAC and so it loads right on Application startup. I don't think there's a way to load a GAC'd assembly just on a page as opposed in Web.Config, which presumably would fix that problem.

All samples have links to view both the ASPX and .cs source online so you can see how things work with the various tools without downloading anything.

NOTE:
If you download the samples, make sure you read the _README.HTM file - it talks about the OWC requirements and database configuration issues you need to configure to get started.