I've actually decided to set Ruby on Rails aside (perhaps permanently) and investigate embedded perl server systems/frameworks, so I can at least say to myself I tried more than one method of accomplishing more or less the same sort of task. I think this would have been difficult if I hadn't done RonR first, because it makes a lot things easy and gave me an understanding of what a web framework is and how it works.
Before I forget, tho, I want to correct myself and say my final opinion on "Ajax on Rails" (which I've now read most of it) is the same as my first impression: it is unusually well written and organized, esp. by comparison to some of the other rails and ajax books I've had the opportunity to peruse. It is not a complete introduction or reference to rails (or ajax); the focus is on the intersection of the two -- which rails aims for a lot of integration with prototype and script.aculo.us. The book includes a complete reference to both of those *and* the various rails helper functions related to them*.
So all apologies to Mr. Scott Raymond for calling him a drunken twerp And anyone who wants a hands on, highly functional introduction to "web 2.0" style programming, try Ruby on Rails. It's like macaroni and cheese in a box.
*which, since Mason does not have these, I am now having to write some parallel functions, etc. myself. Being a control freak and compulsive typist, I actually prefer that (fewer layers of abstraction), but IMO it would be Pretty Damn Challanging without the intro provided by RonR...