Lots of advise for preventing flats from objects, but I gotta go with improper inflation and/or poor tires with weak sidealls.

In both cases, I'd spen the money on Specialized Armadillos. They make one now that has a reflective material on the sideall that's nice for commuters. Heavy? Yes. Not slower than stopping to change flats though. I honestly doubt many in here (if any at all) have a commute with worse streets and more glass than I do. I literally pop 3-4 curbs on my commute on 25mm tires, no pinch flats. I run my Armadillos at 120+ psi to avoid pinch flats and because of my weight, 235lb.