Without ASP.NET V2 which has a precompile option, your best bet is something like this

http://www.codeproject.com/aspnet/PreCompileAspx.asp

If you use a lot of user controls, you might be able to leverage this idea to speed your compile time?

http://www.codeproject.com/aspnet/ascxparser.asp

Couple that with this to automate the process

http://www.gotdotnet.com/workspaces/workspace.aspx?id=ef3d0a73-0468-46da-8780-ede0f12b6f22

Or just wait for V2...

Stephen.