Tracking employee morale

Freakonomics blogs about a website that tracks moods of the populace, now updated for Hurricane Katrina. They propose a similar idea for companies. What would happen if you did a pulse poll of employee morale every day? At Microsoft we do an employee survey once or twice a year, and we take the results seriously enough that some managers I’m sure are tempted to manipulate it by, say, having a party or some other happy giveaway just before the poll. The results would be more accurate if you did the poll every day, and maybe you’d discover additional trends that aren’t obvious. Like how maybe morale is lower (or higher) right after a holiday weekend.