Reddit mentions of Libbey 5139 Restaurant Basics 16 Ounce Mixing Glass - 24 / CS

After getting sick of our nice looking but fragile glassware breaking all the time, we picked up a case of tempered soda lime mixing glasses from a restaurant supply store. We've only broken one in five years, and that involved concrete and subzero temps. The glasses don't look fancy, but they were pretty inexpensive and we have a ton of spares if they do break.

Edit: basically this, but it was cheaper at the local supply store. About $1 per glass.
http://www.amazon.com/Libbey-Restaurant-Basics-Mixing-Glass/dp/B00165FUUS

i already came up with a way to do it. pint glasses are stackable albeit breakable. just turn them sideways & stacked but print a thin spacer to keep glass from banging on glass...or use something off the shelf to put in between them such as a strip of "drawer liner". done.
http://www.amazon.com/Libbey-Restaurant-Basics-Mixing-Glass/dp/B00165FUUS