There seems to be a lot being made on here of only one person actually booking any gigs regardless of who might have gotten the contact in the first place?
I personally think that some of the reasons being given behind this just don't hold up in the present day. We are all discussing this via our PC's, laptops, phones, tablets whatever. So open up an electronic band calender, all show a bit of responsibility in updating it with your availability and then everyone can make bookings and bring home the bacon. The chances of two of you being on the phone at the same time booking conflicting gigs is pretty remote, never happened to me. And you can always "pencil in" potentials while you are finalising things.
I have always found that the people who can't be bothered to find the work (or help with any of the less glamorous necessities) are invariably the same ones who turn up when most of the set up is done, are do their best to get out of strpping down and helping fellow bandmates in general.