technix:
I have a peeping tom of a government (PRC, or I should say a Big Brother of a government) and I don't want them to mess with my correspondence. By implementing this TRNG I can use my Arduino to generate key files for TrueCrypt, feed quality entropy into my OS X or Linux system to improve their crypto (especially GPG) and use that is a quality source for SSH keys.
OS X ... Linux?
If you're using big machines then just point a webcam at a lava lamp (or a street) and cryptographically hash the output images.