I haven't seen a tutorial, but here are a couple ideas:
Linear actuator: Expensive, and it might be hard to find one small enough. The benefit would be that they are electric, and you could hide the batteries somewhere convenient and remote.
Pneumatic piston: Size is probably good, since you can probably find a small piston. You could probably power it with a CO2 cartridge, or something, if you are clever. It might move faster than you want it to though.
Gear drive: I've seen CD players, and similar things, that when you open the lid it opens very slowly and controlled. I can't remember if they all dropped down, via gravity (which won't help you much), or if some opened upward. If you could find something like this, you might be able to replicate it or even just take the parts from it and adapt them. You also might be able to power it with a small motor and gear drive, but the motor may be hard to fit in there since it would have to be oriented in an inconvenient way.
Servo motor: A servo motor (from an R/C model) could do this very easily, and you could probably create a clever pushrod linkage that would allow you to stick the servo somewhere convenient. The downside of servos is that the signals that control them are complicated, and you would probably need to use a controller board, like an Arduino, to drive it. The upside would be that you could make it do very cool things, like raise and lower at different speeds, control multiple servos and other electronic things (like lights) at the same time, etc. It might be possible to not use a controller, and just design a circuit that generates the proper "pulse width modulation" signal to move the servo between two predetermined positions.