2) The Donkey Sanctuary
This is a great organization that rescues abused and elderly donkeys. They give them a place to rest and recover from their lives. They have an amazing store where you can buy cute donkey things or give money towards improving working conditions for these animals.
3) Farren's Dream Dog
Farren is a special lady. She is a talented writer/editor and an amazing person. Earlier this summer she lost her cat very suddenly. Her dog was diagnosed with a terminal illness almost at the same time. She's finishing grad school and facing bills bills bills and no one should do that alone. Give a dollar or two to help her get a French Bulldog!
4) Ampullae of Lorenzini
Sharks and a few other marine animals have gel-filled spots on their noses that allow them to sense electric fields. This is awesome.