I was sitting in a Mexican restaurant last night and a bright yellow warning light began blinking on their frozen margarita machine. The darkened atmosphere made it seem brighter than it would have during the day, certainly it was a lot brighter than the low-battery light on my smoke detector. Flashing lights draw my eye, so it was tough to keep up with conversation, and I found myself staring at the light, wondering just what kind of emergency could be happening in that machine. Were we in danger? Could it explode--should we evacuate the premises? It would have been a tidy excuse for running out on the bill but I doubt it would have held up in court.