Well-documented, cheap, fully open RNG
For Infinite Noise true random number generator
I ordered this little guy while it was on back order (because everyone wants a cheap, open, verifiable source of good entropy), and although I haven't had the time to open it up or anything too crazy yet, it's a fantastic device. You'll have to go to Wayward Geek's Github to get the driver source code for it, and I would definitely suggest looking through the ReadMe file; it has an absurd amount of documentation that you should at least be somewhat familiar with (and the author clearly spent a lot of time and effort on it). It's quite easy to compile the driver (I had some trouble with it not finding a library, but it just took some time on Google, and a couple symlinks to get it working --after that it was really painless), and there's even a driver for Windows (if that's your thing), although I didn't try it out at all.
I ordered the black, EMI-shielded enclosure and it seems quite well put-together, and it looks pretty slick (if you value the appearance of your entropy generators). I never had the need to contact the developer, but given his/her amazing documentation, I would think that wouldn't be a problem.
Altogether, I would definitely recommend checking this out (at least on Github) if you're interested in using/learning about entropy and hardware entropy generators.
