Try a chain hack utilizing Arduino.
Chain hacks are like chain mail but instead of a written letter or message of sorts, the chain consists of a physical item. The further the chain hack gets, the cooler it gets.
It all starts with an idea. There can be an explicit goal in mind or there can be no necessary goal. The idea/item/gadget gets passed from person to person and grows in functionality, creativity and awesomeness.
Basically, when you receive a chain hack, add to it, make it cooler and send it on. You may want to take a picture of it, document or record your addition and send it on. Deliver or send it to a hacker friend. Try to send it to someone that you know that can and will make it better and keep the chain hack going. If the record of the chain hack grows, it would be ideal if the a record of the persons adding to it can be included right on the device, gadget or art piece with a description of what they did. If not, perhaps they could be added on the blueprint be it on some accompanying document or other memory storage device.
If there is an explicit goal in mind, perhaps there can be a cool predetermined final destination or purpose. For example, deliver to such and such museum or robotics department or a soup kitchen or whatever. Perhaps its final purpose is as a San Francisco public art piece, or a keyboard for Steve Jobs. For the chain hack meme to spread, the higher profile destination the better. Upload your chain hack to YouTube, Google Videos or a particular website.
Examples of who to send your chain hack to include electricians, wood workers, welders, programmers, artists, philosophers, designers, publicists, and tinkerers of all sorts. Make sure and ask if the next person thinks they will be able to improve upon the hack. If they can't, try someone else. If you think you can do something, but it doesn't work out, send it to someone who can.
Chain hacks share the sharing spirit of the Internet but are physically tangible at every step.
Be creative and have fun!