You could always capitulate take the path of least resistance and wait until your child decides that s/he wants to do it him/herself. I had to wait until the morning of DS2's fourth birthday for this happy event - BUT it all passed off with a total of three accidents and no stress whatsoever. Whereas forcing his older brother to train before he was really ready was the second-most stressful experience of my entire life, I think.
I think potties need a serious redesign to accommodate boys. Either that or my sons needed a serious redesign so that they didn't spray up-and-over. I avoided toddler trauma by putting them on the potty from about 6 months (once they could sit up) while changing nappies.