I know what you mean about lesson planning, We have 3 digital cameras which need to be booked out 3 days in advance to solve any conflict. The art teacher came to me one day and asked to take one of the cameras, (She had not booked it), and as it turned out they were all being used. I told her they were all previousley booked and are all out. She then asked, In a Very ignorant way, "Well what do YOU expect ME to do this lesson then?".
I cant seem to get it into their heads that there is a limited suply of hardware to go around, and that is why if they need something setup, they need to book it! I would love it if we had an unlimited budget, but we dont!.