Yeah, I'm friends with people who work at restaurants, so I know first-hand how dependent they are on it. Not that I didn't before, though...

Man, there's a lot less bitter argument in this topic than last time.

*In an Ozzie Guillen voice* PEOPLE WHO DON'T TIP ARE FAGGOTS.

This. I usually round up to 20% for delivery guys and servers. I used to not tip the barber, but now I tip them pretty nicely, like more than 40% last time I was there.

I tip according to how my service was compunded with how much the bill is.

$0-20: the tip will be between 0 and 3 dollars, depending on service.
$21-30: The tip will be between 5 and 9 dollars, depending on service.

etc, etc.

Having worked as both a waiter and a delivery driver, I know that I tip too much. I almost always tip 25-50% any time I eat out...which is next to never. Delivery guys get at least five bucks, more if the order was huge and they had to put it in three or four bags or something. But I rarely order delivery anymore, either. I cook instead of going out to eat when I don't have enough money to leave a nice tip, that's how everybody should operate.

I'm not as nice, of course, if your service totally sucks. Two dollars for you.

yes

I just leave my phone number on the table along with a note that says "Call me, baby." That's all the tip they'll ever need.

I actually did that once. I met some friends after they were already done eating, ordered a 24 oz Newcastle on tap(omg so good), drank it, payed for it and left her a good tip and my number.
No call.

Helps if you actually left a tip. Some girl once left me her number but she didn't tip me. That's cool, but she didn't pay the bill either. And she applied for a job at the restaurant during that same visit. Yeah, I'd sure like to hit that.