The Art Of The Split

As far as mathematical operations go, division is a fairly simple one. Arguably, it follows that splitting a restaurant tab among a group of people is a comparably simple task. But, as you may well know, that is rarely the case.
Is money the root of all evil? Probably not, but it is the root of this common socially uncomfortable situation. After a GoingAway dinner for a coworker this weekend, we discussed the subject of check-splitting ad nauseum. Some argued for the iron fist even split: even if you just got a side salad, you should contribute an equal share. The argument here is that restaurants are not grocery stores and you are not just paying for your food, you are paying for the service and for the entertainment value of spending time with others. Most of the people I talked to about this seemed to think this was generally acceptable with a few exceptions.

First, if you ordered seven courses including Prime Rib, while your tablemates by and large chose much lighter (and less expensive) fare, you should not be a free loader and should pony up the extra cash. Speaking of cash, the propoensity for people these days to not carry cash could be the subject of a whole other post (which I'll not actually write). Yes there are lots of good reasons to pay with credit cards, but in my opinion, handing the waiter a stack of 10 credit cards is, well, awful. Go to an ATM once in a while, and carry some small bills as well. It won't kill you.
Secondly, if only a subset of the diners are having drinks, some allowance should be made for that. Those who had drinks should throw in few dollars more, while non-drinkers should get a small break. The main issue here, as in the previous case, is that people should be responsible enough to chip in the extra money, and no one should have to ask them. Why is this important? Because as soon as someone else starts telling the people around them that they need to pay more, the people who accounted for only a small contribution to the total bill will often feel compelled to argue their case for how little they should pay. But guess what? Your $7 doesn't really cover your $5.95 sandwich. No way, no how. Especially when we're covering the GuestOfHonor's tab as well.
Finally, it should be stated in no uncertain terms, up front before ordering takes place, that this will be an "even split" meal. It may be painful and awkward, but at least everyone will know what they are getting into.
With all these caveats, is the "even split" really an equitable solution? Let's consider the alternatives. The most common alternative is the "everyone puts in what they owe" system. This system actually works fairly well with small groups (5 or less typically), and groups of good friends in particular, where no one is afraid to call someone out for not contributing their fair share. Beyond that, the system breaks down because people are stupid, in that they are forgetful, and they are bad at math. Maybe they added tip, but forgot tax. Maybe they forgot about the nachos that we split. Or Maybe they are just trying to get away with something. But how many times have you heard someone say "We're seven dollars short."? Inevitably, someone feels like they are getting ripped off, and silently vows to never go out to eat again because they are always the one having to pay more than they should.
The other alternatively is the ever popular "separate checks" method. Theoretically I think this is a great solution, assuming you can overcome the two small obstacles of a) splitting appetizers or other shared dishes evenly among the party and b)footing the bill for the GuestOfHonor, if one exists. These should both be solvable by putting said items on one persons bill, and everyone else chipping in some token amount. My objection to check splitting, with large parties, is the same as the "stack of credit card" issue above - it is an unnecessary burden on the wait staff, especially if you have more than a handful of people.
So, what is one to do in these situations? If it is suggested that everything be split evenly, be civil and go along with it (with the possible exception of the case where the proposer is the one person who spent significantl more, in which case they should stoned). It may cost you a few dollars more than you would have liked, but, as one friend of mine put it "If you don't want to pay, don't come." If instead, the group attempts the always-dangerous "pay what you owe" system, try this: Check the bill for the cost of your entree (plus salad, drinks, or anything else you ordered). Add them up, and add on 30% (tax + tip + rounding up just to be safe). If appetizers were ordered, add a dollar or two (depending on party size and number of appetizers). Finally if you are covering the bill for the GuestOfHonor, add another two or three dollars, again depending on party size.
Of course, if you are a true player, you could just quietly pay the entire bill yourself, despite any objections to the contrary. If anyone doesn't approach you later and offer to pay their share, I suggest blacklisting them.