Not to be rude, but I'm growing in my closet, with CFL's. Money is kinda a huge deal. Besides, I think a critical point people are forgetting here is that I'm talking about a 22' wide hollow core door. Anyone even halfway motivated to get in could punch a hole right through it. I'm talking about a practical, cost effective solution to keep people who don't know better from opening it on accident. I'm not trying to keep people out who know whats behind the door, thats not practical.
I can't drill any huge holes in the door. No changing of knobs or locks or fingerprint scanners or key cards or RFID or retina scanners or hand print readers or voice activated ANYTHING. I'm talking about dropping a few dollars to keep a guest from looking inside.
So far the best idea (and the only feasible one) was a simple bolt lock locked from the outside using a magnet.