Reuse an old tree to make a log pathway in your garden. Good use of "yard" trees and other wood that can't be milled; works much better in climates without termites. Good drainage under the log rounds will make the path last longer.
Glow in the dark bubbles - open glow sticks & pour them into bubble solution. Link says it's hard to see glowing bubble. but it's worth a shot since they were using a glowing bubble solution not a glow stick.