I have two:
Make A Wish Foundation: fulfills the last wishes of terminally ill kids.
Locks of Love: they make wigs for "chemo-kids" to replace the hair they lose from donated hair from long haired hippy type freaks like me that decide to cut their hair.
From what I've seen both of these charities have relatively low administration costs associated so you know that most of your bling is going directly to providing help to those in need.
I gave up on Unicef and United Way several years back when their admin costs soared above 25%.
Edit and a side note: Here in about a year I'm prolly gonna get fed up with my long hair and donate my long thick locks to them.
