Here's the link, and below is my peanut gallery commentary:
MySQL and Postgres: Simple and straightforward
SQL Server: Simple but odd function name to have to remember to call
DB2: Um, awkward. Can you not just do "order by RAND()" in DB2?
Oracle: So...I HAVE to make a subquery and use rownum? Oy vey. Oracle has a knack for being beyond powerful, but the simplest things can be way too clumsy. Take sqlplus for example.