I'm used to using the "Detach All" function on the debug menu to allow me to go back to editing and compiling, with the intent of re-attaching later.
This menu option disappeared on me after I installed Windows 7 64-bit. I've heard from others that it didn't exist under 32-bit Vista, either.
For the record, the option appears when debugging console apps. So far, I've only noticed it missing on web applications.
Edit: So, if I debug just a simple web application with nothing else in it, the Detach All option is there. Need to find out what is different about the (multiple) projects I've been trying to debug that don't have it.