I like the idea on the Hunslet forum where fans can take away a jar and put anything they want in to it and return it when it is full.
Presumably 1p, 2p 5p, 10p are the most popular coins that people don't want in their pockets or wallets / purses these days,
Why not run a competition over the off season to see who can fill the most jars or have the most money in a jar and the club give a prize out.
At home we put £5 a week in to an envelope when schools go back in September so have over £200 by the time August school holidays come round to spend on keeping the kids occupied for 6 weeks. Not hard to do when you can get it set up correctly.