I don't/can't give to everyone who asks, but I really don't mind people asking.... we had Christian Aid at the door yesterday, I was smiley, said "I already give to certain charities, but thanks and good luck", the lady was lovely and the conversation lasted less than a minute.
For me, I prefer the bag packing system, I've sometimes only put a penny in their bucket (they wouldn't know this) rather than say "No", like I say no one TOUCHES my bags, I don't have a system as such I just like packing my shopping myself. I'd rather see the kids who will benefit from the fundraising doing something pro-active than seeing an adult representative stood at the door acosting me when I'm on the way out... that's my preference.
Being on a PTA and having been on pre-school committees and toddler group committees I know how hard fundraising is, and I know that money is always needed to keep the service going. The local swimming club keeps costs low so all children can be involved, but they stil need to do fundraising events to keep the club open.
It does feel that everyone's a charity these days, but they all need money, donating is not compulsory and no one should ever feel pressure (unless its an internal pressure of the conscience) to donate.