This thread definitely generated a lot more discussion than I expected. Thanks for the input, everyone. I'm kind of surprised that the equal split seems to be by far the preferred method since I'd never seen it done at all before just recently, but live and learn. Just to be clear, I have no problem with the even split beyond feeling a little bit weird about having other people subsidize my food, but I like the idea of offering to leave the tip if my meal is more expensive.
You all might be right that the itemized vs. equal split is a matter of being a poor student vs. a professional with money. I just recently finished grad school and am now in my first real professional job, so that may have more to do with the change in preferred payment method I'm seeing than anything else.
There is probably some truth to the idea that it is an age/generational thing, too. I feel when I see old friends who are my own age, the itemized separate checks are still standard regardless of life situation.
I'm still not entirely sure about the idea that the even split is easier or faster. What could be easier or faster than just asking for separate checks and then everyone paying their personal check? Not a big deal, though, and if the even split is considered more socially acceptable, I'll go with it.