If you can't get seperate checks, then I would suggest you keeping track of what you owe and dont be the one collecting the money. The person collecting the money always gets stiffed in the end. Know what you owe, check the bill first, and put it down for the others to deal with.
I do not like the idea of splitting it evenly. That may be easy, but it just ins't fair. I dont drink soda and I dont always order something that costs a lot, so its not fair for me to chip in my share, my tip plus the cost of someone elses meal. That happened to me a time or two and I refuse to do it. Its not a matter of being cheap, but its a matter of whats fair.
In college I had one friend who had a very hard time when it came to the bill. It wasn't that he didn't want to chip in his share or that he was trying to get away with something. It was just that he didn't know better. He had never been on his own before and his parents up until then had always taken care of the bill. So when on his own finally, he didn't really pay attention to anything other than the price of what he ordered. Just the entree though. If it was $7.99 for a burger, he would put in $8.00. Thats what he thought his part was. After it happened a few times, we as his friends confronted him that his drink, his sides, tax and tip also needed to be included. He honestly didn't know. After we told him, things got better.