Howdy (especially if you got here from Twitter)!  Tipping is one of my sore points, mostly because for 18 months, it made up 50% or more of my income.  I have some pretty strong opinions about it and what (at least I think) are well reasoned arguments.  Here are a few of those:

The Last I'll Say About Tipping
On Slice: How Much Should You Tip on Pizza Delivery?
In case you need JESUS to tell you tip... he did.
Regarding the Delivery Fee

Other people on tipping:

Tip The Pizza Guy

On tipping waiters:*

From "the bitchy waiter"

I Have Been Robbed
A Comment on Comments

 *I know you know how I feel about comparing the two jobs, so this definitely isn't implying anything about how you should tip your pizza delivery person.  With that said, these are interesting and chances are if you need me to tell you why you should tip your pizza delivery person, you could probably use a few reasons to tip your waiter too.