A while back, I came across the concept of Fixed Ratio Position Sizing (presented on http://www.breakoutfutures.com/Newsletters/Newsletter0703.htm). I am wondering if any of the members of this forum has ever experimented with this technique.

I think, it is all about playing with utility function implicitly. I haven't read Jones, but if he doesn't mention utility function or doesn't use it to derive the formula - then he would be a crook.