Out of any of the tips/tricks, etc. I've run across the past year, I think this HAS to be one of the most useful, at least for me.
Apparently if you hit Ctrl + Break when a running build is going on it will cancel the currently running build. I can't tell you how many times I could have used this a few clients ago when our solution had 28+ projects in it. Builds would take upwards of 5 minutes only to find out that you have an error starting you right in the face, that you could have gotten back 4.5 minutes of productivity if you were able to stop the build. No one I worked with seemed to know how. I wonder how many consulting dollars were spent on that project waiting for the build to finish????