Manage costs of a bachelor party

You're the best man and it's up to you to plan the bachelor party. You've got a great day planned: paintballing, ATVing and a party on the lake to cap it off, but you need to get the other guys to chip in on the various rentals needed to have the party. Not all of the other guys are in town until the morning of, so you need an easy way to collect. Something that doesn't involve you paying up front and getting the money from them at a later date, because you know how that goes. And you need a head count of the guys who can make it.