When developing in ASP.Net one often recompiling frequently to test changes and hunt for bugs. If the project is of any size this recompile can take quite some time.
I was searching for information on how optimize ASP.Net recompile and I found an interesting article.
Basically you add optimizeCompilations="true" to the <compile> tag in web.config.
If you have Windows 7 then this will work out of the box.
If you have Windows XP/2003 you need to download this.
If you have Windows Vista/2008 you need to download this.
This will recompile only what has actually changed which results in lower recompile times and less waiting.