MODERN ETIQUETTE II: Since y'all raised it yesterday, let's have at it -- what is the proper tipping level for a taxi ride? I typically pay cash, and I typically round up to the next dollar for a fare under $9 -- $6.XX means I want the guy to have $8.00, $8.XX means $10.00, etc. For fares over $9, I'll round it up higher.
I strongly disagree with Isaac's assertion that because "a cab driver who takes you a very short distance has lost the fare and tip from a longer ride," you should give the guy $10 for a $7.20 cab ride. To me, as long as the driver is taking me somewhere where he can pick up his next fare quickly (and he can if he's taking me home), he gets to grab another $2.70 flag drop (+ $1.25 temporary fuel surcharge) and keep the revenues high. Now, this may be a Phila v. LA thing -- other than airport trips ($28.50 flat fee, and I'll usually give the guy $34-$35 depending on bags handled), Philadelphia cab drivers don't do a lot of long trips to the suburbs because our commuter rail system does a good job of getting those folks home. It's mostly intra-downtown transit. But YMMV.
added.sunstein.nudge.nudge.nudge: Setting the default tip percentages for NYC taxis accepting credit cards to 20%, 25%, and 30% has raised the average tip from roughly 10% to 22%, generating $144,146,165 per year in additional tips.