Not wild about those rolls of fiberglas as bass traps: ugly and bulky! Plus, I'm not sure they'd work all that well. Most bass traps I know of have some sort of rigid shell. A simple and cheap DIY trap would simply be a 2 foot or so wide sheet of 1/8" material like Masonite in the corner at a 45 deg. angle, backed with fiberglas. A piece of pegboard would work, too - the holes would make it function as a "Helmholz resonator". Either way, the sheet is screwed to vertical wooden strips, and runs floor to ceiling.
The fabric covered acoustical tile idea sounds good, though. Another DIY solution I ran across is similar, but uses fiberglas "duct board" with a fabric covering. It's a rigid compressed fiberglas board with aluminum foil facing on one side, used to make insulated HVAC ducting. For our use, the foil side goes against the wall and the raw fiberglas side is covered with fabric. The material supposedly cuts easily, and is also available at Home Depot.