GRC.com has an interesting utility that generates 256-bit random numbers that it displays as strings of random ASCII characters. What’s so interesting about that? Well, these strings are ideal for use as passwords or encryption keys:
Every one is completely random (maximum entropy) without any pattern, and the cryptographically-strong pseudo random number generator we use guarantees that no similar strings will ever be produced again.
Also, because this page will only allow itself to be displayed over a snoop-proof and proxy-proof high-security SSL connection, and it is marked as having expired back in 1999, this page which was custom generated just now for you will not be cached or visible to anyone else.
I don’t know if it’s that much of an improvement over, say, "cat /dev/urandom | strings"– but it is a bit more portable.