There is nothing that screams "your floors are filthy and you are a bad parent you slob" than a crawling baby with dirt all over their pant legs. I thought we kept a reasonably clean home, but once Madame started crawling I realized that maybe everything wasn't as clean as it should be.
I've never been a big fan of the "Roomba" robotic vacuum cleaner, but this new product from iRobot is right up my alley. The Scooba is basically the Roomba, but it washes your floors instead. First it cleans up debris (including Cheerios the demo person said), then it scrubs, washes and rinses the floors. I guess the idea is you turn the thing on, go to the grocery store, and when you come home the floors are clean.
At $400 I'm not exactly running out to the store to buy one, but I'm definitely thinking about it.