[Sami_Lehtinen]

Crappy (free, obsolete) webcam, fm-receiver, tv-receiver + sha512? - Define cheap.

[chrisseaton]

I'm not normally a paranoid person but EM radiation seems like it's something that it would be easy for someone outside your house in a van to manipulate.

[MichaelRenor]

Discussions about random seed generators usually devolve into theoretical issues about why <random idea> can be manipulated.

If you're really paranoid, just do this:

$ echo "<bash face against keyboard multiple times>" >> /dev/random

[Dylan16807]

It should be basically impossible for them to manipulate the low bits of the signal. Then you hash it, which makes any bias irrelevant as long as enough bits are random.