If anyone is in the VA Beach area on Feb 21st, stop by the Hampton Roads UG meeting. I'll be presenting about how to use AJAX within your SharePoint Web Parts. I presented on the same topic back at the Philly.Net Jan 2008 Code Camp and I think it went over really well, and one of the attendees runs the Hampton Roads UG, hence why I am presenting down there.
Luckily for the attendees on thursday, I have updated the material to provide more "real world" examples, as well as some alternatives to using just using the straight MS ASP.NET AJAX framework to do AJAX. I'll be including a few examples using jQuery, as well as the ICallbackHandler to do lightweight AJAX. After attending Todd Bleekers' presentation on the same topic (I still feel mine is better of course!), he did turn me onto the ICallbackHandler idea. Basically, it is a lightweight way to do AJAX style calls from your Web Parts, but as with everything AJAX related, it is to be used with caution.
What I really want attendees to walk away with from this presentation, if they walk away with nothing else, is that SharePoint really is an "application platform" that you can develop on. You can develop your apps using cutting edge technologies like AJAX and LINQ (my next upcoming presentation) for example, for those pieces of the app that need it. But for the majority of your app, that 80% as they say, you can leverage what SharePoint comes with out of the box to achieve that 80%, and then use the other cutting edge technologies on that 20% of your app that really needs it.