A group of us were interested in the Graffiti Research Lab's Throwies and decided to try some for Fiesta in San Antonio. A throwie is an LED, small battery, and a strong rare earth magnet. The cost on all of these items is now low enough that you can make the throwies for under 50 cents each in quantity.
We started out the evening at La Tuna to assemble the throwies and discuss our plans. After building almost 200 throwies we started talking about where to toss them. At least a few of them went on the outside of La Tuna while we made up our minds. We all piled in the van and made our way to the Riverwalk.
At first we just experimented with lamp posts, street signs (most are aluminum) but we soon came to one of the tressel bridges over the Riverwalk. We used up about a third of them on the top of the bridge, handing some to passer-bys that looked interested. Many strangers joined in the fun by throwing ones we gave them and picking up fallen throwies. Everyone thought it was great fun and a cool idea.
Next we trapsed around the river where we tagged a number of fence posts, signs and various vendor and restaurant carts. The undersides of most bridges turned out to be too crowded to risk throwing things but we did manage to light up the beams under at least one bridge.
Before the night was out we returned to the original bridge to see how many LEDs had gone missing. Most of them were still there (the ones up high) so we handed out a few more and added more color to the bridge before heading back to La Tuna. We lit up the back wall at La Tuna with the remaining LEDs before calling it a night.
The whole evening was a lot more fun than I expected with much of the thrill of graffiti without the permanent damage that paint causes. The LEDs should shine for close to a week at which point we'll go back and recover as many as we can to to be recycled and reused.
For some more information about Throwies check out these links:
http://www.instructables.com/
http://graffitiresearchlab.com/
http://www.makezine.com/
[Update:]
Another post about the evening here: http://sweaterproject.org/2006/04/24/concerning-throwies/