Ruby on Rails is an entirely different system than PHP--it's a completely different programming language (Ruby) with its own framework (Rails). While it's fairly powerful, Ruby as a language can be rather confusing.

Smarty is a PHP templating system, designed to do some of the menial, oft-repeated tasks in PHP websites. While I won't go in-depth into it or its competitors (such as CakePHP), I'll tell you right off the bat that it won't enable you to do anything you couldn't do with some time and effort on your own.

I also am a self-taught developer--I taught myself HTML, then CSS, PHP, SQL, Javascript, C/C++/C#, and how to administrate websites on both Linux and Windows, running Apache and IIS.

Based on this experience, I have one main piece of advice for you: the first time you want something, build it yourself without the aid of a framework. You'll learn more about the underlying systems and what they're capable of than in any other fashion. This will help you a LOT when you do start using frameworks, to know when something's possible, when it isn't, and when your framework is limiting you.

In two weeks, I'll start my freshman year of college--and hey, what do you know? I already seem to have a solid knowledge of the language they're teaching, from the ground up. :P Not only that--because I forced myself to learn WHY it works as well as how to use it, I can not only handle the class with ease, but also teach and help others interested in the subject.

Other server-side languages you might be interested in:

ASP.NET (this is actually a framework like Rails that requires one of several languages--I learned C# because of the syntax's similarity to PHP, but VB is very popular too)
Perl
Rails (Ruby is, I believe, the only language that works on the Rails framework)
ColdFusion

Client-side languages on which you'll need a firm grasp:

HTML (4.01 strict is the most common type--do some research around WW to learn some arguments to present to clients that want you to do "XHTML" websites, as this is primarily a buzzword companies like to ask for--there are very few reasons to use true XHTML)
CSS
Javascript

Optional client-side technologies that can increase your worth as a developer:

Flash
Shockwave

Learning SEO is also a must, as many in here will tell you.

Again, welcome to WW, and good luck in the acronym soup!

... most of all of us are busy busy at other things when we stop by here.. mistakes do happen..

Let ME welcome YOU to WW. *evil grin*