Terribly ironic in light of my post-before-last, but it does meet my criteria of "request for help that actually goes to a centralized location"...
If you go to
The Animal Rescue Site and click on the purple box "Fund Food for Animals," their corporate sponsors/advertisers will donate food to abandoned/neglected animals. They do this in exchange for advertising, so for you it's totally free. Apparently they're having trouble getting enough people to click on it daily to meet their quotas of free food donated to abused and neglected animals.
Dude, it takes less than a minute to go to their site and click! Go do it! Every day, even!
http://www.theanimalrescuesite.com/ Thankee.