A question is asked on xkcd in a comic, as a joke, and I just wanted to share some thoughts. (it took me longer to edit and upload the images than get my solution, but I can't find a better one)http://xkcd.com/356/
This is about the question on the picket sign. The knee-jerk path for measuring resistance is this first one, but, as it's a single path with three 1 Ohm resistors in series, it's a 3 Ohm resistance path:http://img.photobucket.com/albums/v14/SaabTuner/nerd_sniping_solutionGimmel_zpsb1d8c8ba.png
Two (or more) resistors incur less resistance in parallel than either resistor(s) alone. So I tried this path, and got 1.5 Ohms.http://img.photobucket.com/albums/v14/SaabTuner/nerd_sniping_solutionAleph_zps6746639a.png
Just to cover other possibilities, I measured these two mirrored paths, both of which cannot flow simultaneously, and each has 2 Ohms.http://img.photobucket.com/albums/v14/SaabTuner/nerd_sniping_solutionBet_zps016b56e5.png
If anyone can find a path with less than 1.5 Ohms, that would be awesome. The math for the green paths acts as though the three resistors in series on each path are one 3 Ohm resistor for simplicity. (it's stated as an ideal case, so there you go) For two resistors (or paths of resistance) the total resistance is multiple over sum. [(3*3)/(3+3)] = 9/6 = 3/2 = 1.5 Ohms
p.s. That's how you can be sure I'm at least moderately nerdy.