i'm trying to figure out whats the best way I can do this..

i want to create a unique string either based on userid or email for personalized urls sort of like how youtube is:
-- does anyone know which approach I should take on this?

__________________
"Things you can get access to, you should never memorize." -Albert Einstein
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin