This Death Cartoon from Bizarro shows that even a gorilla (or is that Bigfoot?) can do end-of-life planning. This sets a good example.
However, be aware! If you are planning to leave your body to science in exchange for a free cremation, I highly recommend you read this Reuters investigative series, The Body Trade: Cashing in on the donated dead. In the U.S. market for human bodies, almost anyone can dissect and sell the dead. Companies are making millions from people who want free cremations – but they may not be using those donated bodies in the ways you’d think.
Consider making arrangements with a medical school anatomical gift program first, and use these other organizations as a Plan B if the medical school option falls through.