I was at ACME yesterday, and things got really out of hand with the coin line.  There were somewhere between 8-15 people who wanted to play at any given time, something like six quarters up, lots of frustration, and very little satisfaction with this system from anyone.  When xenonscreams asked me how we do lines here, I honestly didn't even know what to tell her, since our rudimentary attempts at coin lines are often foiled by the fact that quarters all look the same. 

BACK IN MY DAY, we used to do card lines.  I don't know if I could convince everyone who plays around here to transition to this method, but it was much more cut and dry and significantly easier to understand.  Each person used a different card so they were easy to identify (even if it wasn't something like a business card with your name on it, people generally knew who used, say, the Safeway club card.)  This is my proposal.  I'd like to hear other suggestions, though!