DIY Omnibounce using Foodsaver bags. The thicker Ziploc bags works too. Don't need the machine. Just scotch tape the plastic together. Folds up flat like a sheet of paper, yet pops open like an Omnibounce - no more bulky tuppeware diffusers. And the sleeve allows for inserts of other diffusers/reflectors such as paper/vellum/tinfoil!
Pictures from the "Disappear Here" set were taken with this DIY Omnibounce, with a white paper reflector inserted: