If, like me, you're tired of waiting while your /dev/random scrapes the bottom of the bit bucket for entropy, or if you're a project admin that may be interested in augmenting your system entropy with a little help from a bit of USB connected kit, there's a kickstarter project currently underway that may be of interest to you:

OneRNG - an open source entropy generator

Open source software, open source hardware, what more do you need?

---

ralic's law of forums: Irrespective of any prior research done, you will find the solution to your question shortly after posting it to a public Internet forum, resulting in readers concluding that you have done no research on the matter whatsoever.