Water faucet extention. Can be helpful for those in a wheelchair or small children who have trouble reaching their hands all the way under the faucet. Very handy, can be made out of basically any plastic bottle or cup, is inexpensive, and easy to create!
Do It Yourself - Straw Holder.
It could be arthritis, muscle pain, or any other disability that does not allow them to even hold a spoon when eating... This will help!
Full instructions at http://www.instructables.com/id/Assistive-eating-universal-utensil-holder-almost/
Switches are expensive! Sometimes, it's handy to make your own.
Full instructions at http://www.instructables.com/id/CD-Switch
A battery interrupter is a tool that adds a switch jack to (aka "switch adapts") an electrical device.
Full instructions at http://www.instructables.com/id/No-Solder-Battery-Interrupter