http://www.weldingtipsandtricks.com/broken-tap.html From time to time I see threads asking how to remove broken bolts, studs, taps etc. I came across this vid. Pretty cool. Guy makes it look easy.
One of my favorite websites. If you sign up they will E-mail a video every week with tips for welding. It's free and the archive is a list of past videos that you can watch anytime for help.