Often your application needs some form of UUID. For example for "Secret URLs" or Persistent Logins. I found the uuidtools to be very useful for this task. It allows you to create various forms of UUIDs (i.e. MD5, SHA1, Timestamp or Random).

Get the gem [code]sudo gem install uuidtools[/code]

And generate UUIDs[ruby]UUID.random_create.to_s

UUID.timestamp_create.to_s

[/ruby]

and thats all there is about it.

Resources:

RFC 4122

uuidtools API