<p>It's really annoying that visual studio hides typos in aspx pages (not the code behind).
If the compiler would compile them, I would get a compile error.</p>

Resharper will catch errors in code  ofASPX pages, all without compiling. works well imo, and better than later compiling.
EDIT: Resharper also has a Solution wide error checker. 'Resharper->Windows->Errors in solution'. It will analyze your entire solution and give a consolidated list of everything it finds, INCLUDING aspx files.