Oh, and I forgot to add a few points. I work in the bar area a lot, that's where the real $$ is.
If you decide to go out drinking and you sit there for a long time and have several beers, please leave more than $3-4. Even if your tab is only $15 dollars you have to keep in mind that when you hold my table up for hours and then only leave a few bucks, I actually LOSE money from you being there. Servers make money when they can turn a table several times. A good rule of thumb is to tip $1 per drink, especially if you set there all night.
Oh, and the jokes about the Sunday morning crowd are all true. The absolute worst tips come on Sunday mornings. I think because most people tithe %10 at church they decide to tip the same. I can't figure it out. But it's ok because they always make sure to leave me the religious pamphlets too