Mending: Armpit Rip

I've been finding a number of really nice tutorials on About.com under the DIY Fashion category. This one explains how to mend an underarm rip.

It has clear illustrations for repairing a rip in the armpit of a shirt including a section on how to make a gusset to fit (assuming this is not a simple seam repair).

This tutorial would also be useful for altering those too-tight underarms on blouses and workshirts.