ASP.NET 2.0 makes 'AJAX' like functionality pretty darn easy :)

Bertrand Le Roy, one of
the rock-star developers on the Web Platform and Tools team has been
doing a lot of work lately using the new out of band postback features
of ASP.NET 2.0 -- you've probably heard of AJAX at this point and this
blog begins to discuss the history of the technology and lots of
awesome ways that ASP.NET 2.0 makes it super easy for anyone to take
advantage of out-of-band updating of web pages without a refresh using
XmlHttpRequest -- check it out!

https://weblogs.asp.net/bleroy/archive/2005/04/08/397761.aspx