I have 7 kids, 15, two 14 year olds, 13,5,3,and 8 months. All have been pottey trained before the age of 2(this is an area I'm good at just don't ask me to take their bottles away :) ) at about a year and a half I put the potty chair in the bathroom and when we are in there they sit on it and play so it is comfortable to them, within the next month when either my husband or myself are using the potty we would remove there diaper to "join" us, eventually you'll notice them usung it, but here is the key to this just like you I let them run naked, I move the potty to what ever room we are using, kitchen, beedroom ect, and there is going to be accidents after it happens take them to the potty, sit them down and explain this is were the pee-pee goes.I find it takes about three days and you really do need to plan it so you are home for most of those three days, stay away from pull up they are the kiss of death the only good theyu do is make sure that the parents don't have accidents to clean up, once they are doing it put underware on and understand there is going to still be accidents because you've just added a barrier ( keep moving the potty around with you) I have found with in a couple of days they have accomplished this new goal, know to quit moving the potty around and thats acctually the easy part just start moving it closer and closer to the bathroom, one more tid bit I live out in the country and trips into town can be long so I carry a potty with me, we pull over and they go just carry bags. I never resort to Pull -ups they are just glorified diapers I hope this helps, The actuall potty training can take a couple of weeks but start the introdution to the potty early and it goes easy......Lot of luck.