I'm supply.
When I have been left with the, "makes notes from the book then answer the questions"
After 1/2 an hour I put the time in the margin where the student's last word is, sometimes it is just the date. I then leave a note for the usual teacher sayng that's what I have done.
I also have a pack of logic puzzle cards in my bag for when no work has been left or I'm covering a tutor group.
I also have pens, bright sparkly pens, with "stolen from Ms X" on them. I was fed up of losing pens, I still do lose the odd one but no where near as many.
When I use a powerpoint the students have a gapped handout to fill in the important parts, it means I know they have got the most important bits and I tell them to use their own definitions. At one college the a group were given netbooks so I put the handout online.
To explain cell membranes / diffusion / channels buy a bag of ball pool balls and a couple of brightly coloured foootballs. Stand a group of students (5-6) in a circle with their legs 30 cm apart and let the rest of the class roll the ball pool balls at the 'cell' they tend to throw them but they don't hurt and you end up with the balls 'diffused' around the room and in the 'cell'.
One of the students in the cell membrane is a calcium channel, they take hold of the calcium football and bring it into the cell but the other students can't.
Repeat with other channels.
When I'm in my other subject and explaining different topologies of computer networks I have students arranged in different topologies, instead of packets of data they pass packets of sweets around the topology.