ASP.Net 2.0 Callbacks: Using callbacks to create a rich Web UI

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/aspnet_20_callbacks_using_callbacks_to_create_a_rich_web_ui.htm]

I just had an article on ASP.Net 2.0 Callbacks published in .Net DJ. It provides a basic intro, and some more advanced uses like handling multiple callbacks and passing multiple data values.