I do save my change, and take it down to Asda or Tesco to to coin counting machine about 2 or 3 times a year, usually it ends up in my pocket and gets spent of cakes or chocolate.
However, three years ago, I asked family and friends to empty their purses and wallets of all change (20pences and smaller) on a Saturday afternoon, and save in the four weeks prior to my birthday party, instead of bying me a present for my big '30' I wanted to give the money to the local Children's Hospice.
On the night of my party 85 people turned up, and some deposited their change into the buckets - there were buckets on the bar too for loose change from buying drinks.
Just over £600 was raised for charity in this way ... however on that occasion I did sit and count and bag it all up, ready for the bank, so that I could send a cheque instead of turning up with several buckets of coins.