Invoking multiple tasks that are slow or lengthy always poses a challenge in front of developers. Normal approach is to develop a multithreaded component and delegate the tasks to it. In ASP.NET 1.x there was no direct support at web form level for executing such tasks in asynchronous manner. ASP.NET 2.0 on the other hand allows you to execute tasks asynchronously from within the web form itself. This article explores the two possible approaches with examples.

http://www.dotnetbips.com/articles/displayarticle.aspx?id=489
http://www.dotnetslackers.com/ASP_NET/re-18447_Invoking_Asynchronous_Tasks_in_ASP_NET_2_0.aspx