Hi, I'm pretty sure there is a number of options to achieve this, so I'm asking here. I often need to generate small unique tokens (like for invitation codes or unimportant authentication token). In the past I've been using Digest::SHA1.hexdigest(some string) which gives us something like "d2b7882fa08bb6de8dca62f16298683bfe4f0738". It's not very user friendly though, and definitely not small. More recently I've been using ActiveSupport::SecureRandom.base64(6) which generates "Xst7JGF6" or "zXxWY/Y/", but sometimes it contains non-url friendly characters like "/". What do you use ? Is there a specific gem to achieve this in a robust fashion (= making collisions unlikely, and specify the characters to be used, like mixture of numbers and characters for instance ?) cheers and thanks for your input, Thibaut -- http://blog.logeek.fr http://evolvingworker.com