This is probably old news, but if you temporarily need to take an ASP.Net Application offline, simply drop a file called app_offline.htm into the root directory of the app. This could be helpful when upgrading a live app. That way, you don't get the ugly...
I posted this on my GeeksWithBlogs blog a while ago (3 years)... I've gotten a few questions about it recently, so I figured I'd post it here and see if it's helpful. Ever wondered how to reset IIS on a remote (local network) machine? Pop open the command...