A brief update:

• Discovered adhesive to the underside of the breadboard. Mounted breadboard (crookedly) to the "fork" of the exercise bike. Made wiring slightly more complicated, but ended up making the overall setup more compact. Also, sensor is now closer to the magnet as it swings by on the wheel, should improve accuracy.
• Ended up packaging Arduino into an iPod box. Not to be pretentious, but because it was the perfect size to fit the Arduino into, and to have sit on the frame of the bike. Currently, +5V, Signal, Ground, and USB all come out of small hole in the top of the box.
• No longer dealing with stack of boxes next to the bike, and everything is glued or taped down to stop it from slowly vibrating away from where it needs to be.

Future improvements:

• Get a bigger LED to indicate revolution detection, maybe expose said LED on the outside of the box. Might be annoying, but certainly useful for debugging.

Fun discoveries:

• Problem solving is a lot more fun while trying to finish the Mike's Hard Lemonade nobody will help you drink. Nobody.
• I may have a beetle problem. Killed about six of while them I was downstairs. Not sure if they were just survivors from when I left the door slightly open while painting, or they're getting in somehow via windows, doors, cracks, pipes, etc.. Sprayed insecticide liberally. Note to self: don't eat off the floor downstairs.