I know that the cutomary tip for a waiter is 15% of the bill.
What is the standard for delivery people (esp. restaurant deliveries)? Cab drivers? Barbers?
YMMV, but:
I tip between 15-30% at a restaurant, depending on service. (Many of them make only half of the minimum wage)
Restaurant delivery, 15%. (They usually make more than minimum wage, and don’t have to keep coming back to check on drinks)
Cab drivers, usually 15-20%. (Most are happy with a couple of bucks, unless it’s a longer trip)
Barbers/Hairstylists, at least 20%. (They do determine if I look like an idiot for the next month or so)
Bartenders, $1.00 per drink, unless it’s an expensive drink. (This one is as close to karma as you can get, I get triple pours in places I frequent)
This question just came up the other day. I can’t find the thread right now, but a quick search on Google turned up this as the first site.
http://www.tipping.org/tips/TipsPageTipsUS.html
I did a bit more looking around and found the thread which is current in IMHO. It was some further pretty good links and info.
http://boards.straightdope.com/sdmb/showthread.php?threadid=72303