555 Timer Hacks: Cable Testers, Magnetic Stirrers, and Lego Grabbers Oh My!

Please visit my Instructable for an introduction to the 555 timer, pinouts, and several applications for the 555 in astable mode: http://www.instructables.com/id/Hack-Your-Snap-Circuits-a-Minimalist-Very-Few-Co/?ALLSTEPS