Ruby snippet: Generate a ten-character random alphanumeric string
a = ('A'..'Z').to_a+('a'..'z').to_a+(0..9).to_a
(1..10).collect { a[rand(a.size)] }.join
That’s 839,299,365,868,340,224 combinations, if you’re counting. Handy for creating unique, relatively-unpredictable URLs.