MacGnG

The following sites have a "click here to donate" feature which costs you nothing.
The sponsors (advertisers) pay out per click.

Time-sensitive! Cick now!
http://www.dannon.com/dannon_cares/ffa/index.php

CANCER
http://www.thebreastcancersite.com*
http://breastcancer.care2.com
http://www.cancercharities.com

HEALTH
http://www.thechildhealthsite.com*
http://www.aetna.com/index.htm (Click icon at upper right.)

TREES/RAINFOREST
http://www.therainforestsite.com*
http://rainforest.care2.com
http://www.redjellyfish.com (save rainforest/feed chimps on the right side of the page. must register)
http://www.tree4life.com/ingles/ingles.htm
http://www.watersite.cc/
http://www.cliquesemiarido.org.br/eng/default.asp

OCEANS
http://oceans.care2.com

POVERTY/HOMELESSNESS
http://www.povertyfighters.com
http://www.solvepoverty.com
http://www.bigskysoft.com/~homeless/index.php3
http://www.endhomelessnessnow.org

HUNGER
http://www.againsthunger.org
http://www.stopthehunger.com
http://www.hungrychildren.com
http://www.clickfome.com.br/english/index.html
http://www.dannon.com/dannon_cares/ffa/index.php

ANIMALS
http://www.theanimalrescuesite.com*
http://bigcats.care2.com
http://primates.care2.com
http://www.ecologyfund.com
http://www.care2.com

LANDMINES
http://www.clearlandmines.com

COLLECTIONS
http://freedonation.com
http://www.quickdonations.com
http://www.domypart.org

PREGNANT WOMEN
http://www.thebirthsite.com*

*These sites have a search feature that donates more per search.
It shows up in the bottom right after the initial click.

Thanks to the original post!