Randall Munroe of XKCD fame (my favorite web comic) has created a bash.org of Limericks.
It’s a good mix of obscure geek humor and the more traditional lewd creations.
You will find metapieces like this one:
There once was an X from place B,
That satisfied predicate P,
He or she did thing A,
In an adjective way,
Resulting in circumstance C.
Enjoy The top 250 Limericks.