These exercise all concerned themselves with "connectedness" of points. I don't really know what connectedness means - in my sketches, I kept just drawing a line connecting the points. So I tried to think in terms of association of points, not just literal connection.
There are two static solutions: one connecting two points, one connecting three. The two point program is a somewhat literal interpretation of "connected"; the two points clicked on are connected by a (crooked) line. (Actually, the nearest points in the background grid are connected - downsampling the user's clicks is a nice way to limit the control of the design). The three point program is a bit looser in interpretation: points are no longer connected, but are simply the central points for a figure. Random arcs fill out the rest of the space. I like this one the best of the programs I did this week.
The animations explore the use of time, unfortunately at the expense of a nice final static picture. The short solution actually draws a line between the two points, albeit a line constructed out of little blocks. The fade-in of the blocks was tuned to give a sense of constrained motion between the mouseclicks. The long solution doesn't even draw any sort of graphic between the selected points, animation is the only association between the two mouseclicks. There's an overlap between each frame (nested circles) - that helps smooth the frame transitions. The circle shrinks or grows slower the smaller it is, giving equal visual weighting to each frame.