Magnets, contrary to their name, act like gravity fields; they pull in (or, push out) 'magnetic' objects with a customizable force. The magnet will be 'off' if the force is set to 0 Anything over 0 and the magnet will be 'on'. Because the force is a blue formula box, you can use Ruby or a formula to turn it on and off, and modify the power in real time. If a negative value is used, the magnet will repel magnetic objects.
In SketchyPhysics 2Edit
Some users will remember how buried in the files of the 2nd version of SketchyPhysics was a "magnet" joint. This failed joint could not be accessed through the usual joint interface, and had to be copied into the model from the source. Of course, this did not stop some users, who tried to use it in their models. Unfortunately, the bad joint had been put off limits for a reason; it was unstable. The magnet joint had lots of confusing settings, and connecting it to an object ran the risk of the object disappearing.