Appropriate sources of entropy

Any cryptographic PRNG needs to be reseeded once in a while, and some dubious data will do
just fine for that, given that it is mixed in in a cryptographically secure way. A box with
only a network connection is a good example of that -- it does not have much real entropy
coming in. You say that in absence of any trusted entropy a crypto PRNG is never to be
reseeded. I would disagree. One of the problem is what would happen if a seed file, which
stores state across reboots, is compromised. Another acoounts for any sort of weaknesses found
in a PRNG itself. If you need more details, see Schneier's Yarrow design paper, I could only
agree with what he had to say. The point is, sticking to the one initial seeding forever is a
bad idea.