Friends and Money: How do you handle restaurants?

I've been thinking about our friends and their money a fair bit lately, and about how people behave with it, what they spend it on and what they scrimp on. Of course I wouldn't want to be judgmental about any of it, lest they be judgmental about our silly money games and expenditures, haha. And though they're rather disjointed thoughts, here's what I'm thinking about particularly today:

How do you handle the inevitable check-scramble when dining out with friends? You know, when it's a party of eight, and everyone has shared a pitcher or two of sangria, and gotten appetizers and entrees of varying sizes and prices. Is it more annoying to be the guy who nickle-and-dimes everyone else ("I think my total, based on the three nachos I've eaten and the one glass of sangria I've drunk, is $8.34"), or is it better to just divide by eight, with the sort of universal philosophy that everything evens out in the end? I've been on both sides of the coin. When you're broke it's really frustrating to have to chip in for your friend's deluxe sushi dinner when you only had, you know, the vegetables-and-rice special. And I've said, "Sorry, but this is all I owe," likely to the chagrin of a dining partner or two. Do they have a right to be annoyed at that? Maybe. I've been privately annoyed when my friends do that to me. But following the rules of etiquette, personal finance, friendship and everything else, I just don't know what the right answer is. The right answer could sometimes just be "separate checks," but that isn't always allowed at restaurants, depending on their policies (and again, if you're at a sharing-food sort of place, it wouldn't work, anyway). I find that I become the nickel-and-dimer when I'm broke and it's a long way til payday, and I'm a little more generous to the group till on payday. Knowing how I myself operate should make it easier to sympathize and understand when others--okay, not shortchange the group, but get serious about paying for their side salad and only their side salad. Why is it so easy to be annoyed, though? Why am I not enough person to see the signs of others' financial difficulties and just say, hey, your dinner is on me? Unfortunately, for one thing, you never know until the end of the meal that the money issues will happen and two, feeling like a charity case is also pretty crummy.

So what do you do when you eat out in groups?