I did a search on 'razor blade banks' and a company called West Coast Shaving sells them for a dollar each.
Yeah, I remember having medicine cabinets with a razor blade disposal slot in the back. Haven't seen one in a while, though. the next time I'm at Lowes I'll have to check just for grins.
Yeah the cabinets at my parents house have those...always thought it was dumb because you just get a big pile of blades in the wall behind the cabinet and when you go to renovate the bathroom and rip out the cabinet 200 blades pour out...I just took an old 1/4 pound metal box for loose tea (twinnings) knocked a slot in the lid with a 1" chisel and got a swanky blade bank. It's also all steel so i can just recycle the whole thing.