Or waiter. Or sushi-chef.
I've only got anecdotal evidence supporting this, but the impression I get is that with tighter economic times people are eating out a little less, and tipping a LOT less. The restaurant managers I've spoken to (I know a few, yes) have said that average tips have dropped from around 18% to around 10%.
Sure, sure... a lot of us look at tipping as a way to reward excellent service, and will withhold a good tip from a lousy waiter or waitress. But that's not what's happening here. What's happening is that a lot of us don't want to give up eating out, so we're cutting back on our tips.
1) Be the guy (or gal) who tips well. Start at 20% and round up. Factor that into your budgeting.
2) Crummy service? A low tip just says "I'm cheap." Unless the service is absolutely execrable, it's not really your job to discipline your server. Tip your server well, and then call the manager over and complain. If it was really that bad you'll probably come out further ahead than if you'd skimped on the tip. If not, well... you don't want to eat there again.
My friend Bob has a great policy when he eats out with a large group. He hands the unsuspecting server a $20 at the beginning of the ordering process and says "I want to make sure this is a great experience for everybody... including you." At the end of the meal he strongarms the rest of us into tipping a solid 20%. Funny thing... when Bob's around we ALWAYS have a great time at the restaurant.
But you don't have to go the extra mile. Just make sure you don't skimp. Waitresses and waiters are feeling the crunch at least as badly as the rest of us are.