On the list of what's new in ASP.NET 4.0 you find "Prealoading Web Applications".
If you are running ASP.NET 4.0 on IIS 7.5 you can ask sites to be preloaded when the Internet server starts up (or restarts).
It sounds cool, and a good thing that you are now able to reload heavy services, but I can help thinking that it is also a solution to a problem which should exist. The IIS should handle the Internet communication, while leaving the heavy data processing to services outside of the IIS. These services would should be implemented as services on the server, No?