J.M.
When I was transitioning out of diapers, I just started changing her in the bathroom next to the potty. Off would come the dirty diaper, and I would have her sit on the potty for a minute or two. If she was poopy, I would have her lay down on a changing pad (they really are everywhere... you could even just get a sheet of plastic) while I cleaned her up, then put her on the potty again.
When she seemed to grasp the idea of using the toilet, I took her completely out of diapers at home. She had a few accidents, for a while, but she got the concept pretty quick. She has been out of diapers while at home ever since she was about 15 months old.
I still use pull-ups on her now (at 26 months) for leaving the house... Mainly so that her mess stays contained on the rare occasion that we go somewhere without immediate access to a restroom, and she has to go.