A couple of things you may want to consider:
Give a time that the cameras are to be turned in. Find a 1-hour developer in your area and have them developed. Most throwaway cameras comes with the option of having a disc.

The disc can them be uploaded so that other members can see the results, and those with email addresses can have them sent to them. For those who do not have a pc,you can send them via mail for a cost, which will offset your postage cost.

Make sure that you know which kid turned in the picture so that they can be given credit for each photo. This will encourage those kids who did not want to take a camera to do it the next time. the following year, booklets can be sold at the reunion as a means do have seed money for the next host/hostess. Remember that most people leave early on the last day to travel back to their homes.