[kgeist]

If you look up videos on YouTube, you'll see that they allow visitors to stand between the lava lamps and the cameras (sometimes even entire groups!). And I've always wondered: doesn't that reduce entropy, since people usually wear monotone clothing? And if the lamps are so important, why would they allow that? Maybe the lamps do contribute something, but their system most likely already generates enough entropy with or without the lamps...

[hekkle]

It also depends on how often samples are taken. If it only occurs every hour, Fred in his white shirt is highly unlikely to be standing in the exact same spot still.

Remember, these are only seed values, a pseudorandom number generator will run indefinitely, but from what I understand, CF re-runs these periodically with different seed values, to stop people finding the pattern.