The RNIB (or their agents) call me every year for the raffle. I always refuse. I have an RNIB collection box at home which collects all my coppers (and 5/10/20p coins which I generally don't take back out either). They got £59 in July from that, which is probably about the fouth time I've banked all the coins and sent them the money.
I happen to think that is a good fundraising idea and solved my problem of collecting coppers I wasn't prepared to take back out and use again.