At Qantas we have UNICEF envelopes in our headset packs. We collect the donations at the end of the flight, the idea is that you will donate your foreign currency coins that you cant exchange anyway. We dont shove it down your throat, its a subtle hint if you CHOOSE to do so.
Ive had people put tens of dollars in those envelopes and people who just get rid of their 20c piece... it all counts and any of it is generous. But lets not belittle people for not partaking... we get taxed so much every year yet our governments are too busy sending people to war than help any charities themselves.
Good on you if you do, good on you if you dont.
NEXT!