D.M.
Okay, so this is tricky. My son is almost 3 years old (yikes) and we've just started. I don't think is about manipulation or testing limits, it's about being ready and comfy with the process.
My Mom, me and his teachers at preschool, do potty checks and we take him to the toilet and have him sit on his potty chair. Even if he doesn't go, we wipe, flush and wash our hands. We try to do this every hour, so that he gets used to the idea. Boys are tougher than girls to potty train. But, there is a great book by Elizabeth Pantley that I read and loved that helped me with ideas and how to encourage my son.
Even his preschool teachers say it's a road that shouldn't require battles or being forced...just be patient and consitent. I have a co-worker whose little boy didn't potty learn until 4, so it's a challenge we just have to offer guidance.
Good Luck!
http://www.pantley.com/elizabeth/books/0071476903.php?nid...