Get the flyback transformers out of the monitors, you can have all kinds of high voltage fun with them. Its the largest component besides the tube ( it has a heavy wire running to the tube with a suction cup covering the connection). There are alot of other usable parts from the monitor and main board too( caps,transistors, small transformers, diodes, IC's, heat sinks ect).
Get some power supplies from the towers and there are some cool motors in the drives( CD rom).
Laser diode and optics, gears, micro switches, springs ect ect.
sam