My go-to solution for random id numbers which programmers frequently need

gistfile1.rb

# yields an 11 digit number in base-36
# with an equal probability distribution for all digits
(0..10).to_a.map {(rand*36).to_i.to_s(36)}.join

# this is slightly preferable to the more simple
(rand*(36**11)).to_i.to_s(36) 

# because any number so generated will occasionally be "short"
# and because the first digit will follow a non-random distribution
# in terms of frequency due to some strange number theory thing
# that was only proven in the last decade i think

Thanks, I’ll definitely keep that in mind. A nice thing about UUIDs though is that they don’t include o, i, l and some other chars which makes them a lot more readable. Of course that may not be necessary for everything, but for some use cases it’s great. Also iBeacons :)