T.P.
Hi H., you have already received some good advice. My experience is that you can start with getting them familiar with the potty concept well before they walk. I bought a Baby Bjorn little potty when my daughter was 6m old because she was VERY obvious when she needed to poop and always peed about 5 sedonds after I took her diaper off to change it. I began when she was able to sit on her own. I would sit her on the potty (on the floor on a towel next to the changing table) after every diaper change and she would actually pee about half the time. I knew it was just because she would be peeing if still on the table, but it at least got her familiar with the concept of sitting on a potty. Now at 9m old she regularly poops in the potty before her nap (I went almost 2 weeks once without having to change a poopy diaper) and gets excited when she pees in it. I clap and sing the "yay! peed/pooped in the potty!" song if she goes, and if she doesn't I just pick her up and put on her diaper. I'm also using the sign for potty so she can learn to let me know before she can talk. We also use cloth diapers at home (but Im lazy and use disposables when out and about). I'm hoping this all will help her potty train easier when she is able to recognize her need to go and more easily communicate it to me. Good luck with whatever you decide to do...but I say give it a shot now!
Right now I only do this at home. I don't worry about it when she's at grandmas or at the sitters (1 day a week). My best friend who watches my daughter also does it too when watching her here at home. As she gets older I will start being more consistant with taking her between diaper changes and when not at home. Right now it's not for "training" per se, just to get her used to the potty so training later will be easier. Oh yeah, and not changing poopy diapers is a big benefit!