This is absolutely my fav lightbulb joke:
How many Quantum physicists does it take to change a lightbulb? (version two)
Depends on the room size--you need to fill the room first with blind-folded scientists. Then, upon a signal, they all remove the blindfolds and look toward the general area of the 'old' bulb. Then, when the waveform collapses, whoever is CLOSEST to the newly 'congealed' bulb, grabs it, and WITHOUT blinking, makes the change. Also, this procedure MAY required one additional physicist to remove a dead cat from the room......