Infants being potty trained?!

I came across a womans blog where she was sharing how shes trying to get her 7 month old to use one of those portable potty training toilets. Is it just me or is that the craziest thing you've ever heard?! I don't know when Graigs about to go to the bathroom and when I do it's too late! And there's no way in hell he'd sit there until he went. Did you try this or have you heard of it before?