Do you ever find that your entropy pool is too low? I know we've all been there! Most modern servers come with a hardware random number generator with their TPM, but if you have an older server or are running a crypto heavy service (like an SSL proxy) then you might want to try out the ol' entropy key.
To check out how much entropy you have on your Linux box do this:
cat /proc/sys/kernel/random/entropy_avail
If it's less than 100 then you might have an issue, all depending on what you are doing at the time of course. The Linux kernel actually blocks reading from /dev/random
if the entropy pool isn't entropic enough, and some programs will demand to get their randomness from /dev/random
(as they should!). So a lack of entropy can sometimes cause a process to hang, or, you know, not give strong random numbers.
The entropy key also lets you setup a entropy server that you can use to serve entropy to other computers on a network, which I think is really cool.
So, if you need more randomness in you life, check out the entropy key!