Most charities are just cleverly disguised tax shelters. This is now the hot setup for athletes and Hollywood types to bypass their taxes and give high paying jobs to friends and family members while keeping more of their money.
While the spirit behind large charities such as WWP, United Way, Susan G Komen, etc can make for a feel good story, it is ALWAYS better to donate local. A quick Google search should return a smaller, local charity for your cause of choice. Much smaller overhead (which means more money to the cause) with the added bonus of helping someone in your own community.