I love to see home grown AT. Assistive technology doesn't need to be expensive or complicated.
The first is a mechanical switch a teacher made out of acrylic and is available from Teacher Tube. I haven't had a chance to explore the rest of the site, but I'm intrigued. Link to Video or watch below
The other piece of AT is an electric spinner which could be adapted to allow a child who has difficulty rolling dice or spinning a dial to spin the wheel using a small motor hooked to a switch (think Twister or Chutes and Ladders). You will need Quicktime to view the video <Link to Video>