Looking into both options, thanks for the suggestions. We don't want them to call the venue, they would probably get one of the teenagers who work there and they wouldn't know anything about the concerts. We've found a cell phone (Virgin) which you can buy for $40 and there is no contract - pay as you go, $.25 a minute for the first 10 calls a day and $.10 per minute for the rest. We have no idea how many people will be calling us!