I refuse to give money to anybody who comes asking for it.
Including my in-laws.
I quite loudly proclaim this to any spruikers (link is for AB) that accost me in the street or in shopping centers.
I have had arguments where they have accused me essentially of being cheap or tight. These arguments have usually ended when I've asked them whether they are paid on retainer and commission or salary or they are unpaid volunteers. EDIT: Yes I know they get a shitty rate but you find very few who are volunteers or on salary - which means every $1 you put in the tin, they get a percentage. Hence my reticence to hand over my hard earned bucks to a charity that "employs" people to basically try and harrass you out of some change at your local shopping center.

I do give to charities - the one's I choose, when I choose to. Fortunately here in Oz every donation over $2 is tax deductible - so I get my warm and fuzzies whilst still being a stingy bastard.
2 excellent charities I donate to, if there are any benevolent billionaires out there looking for someone to bequeath their estate too -
www.cathaven.com.au/
www.swananimalhaven.asn.au/
EDIT: & in the interests of full disclosure, I work for neither of them.
(Misery McUglywife an attention seeking sociopathic fuckstain., Tue 28 Feb 2012, 7:52, Reply)