Ok, I would now consider myself good with php and mysql. Although the error handling is not that great, but all together they are great tools.
After I finish with this site I am working on, I want to make a good portal site. Something that can be passed around for easy use. There are not too many portal systems out there. And those that are are kinda cookie cutter. They all seem the same.
I would recommend everyone learn php. I am looking at about $1,000 for the site I am working on. It is a rather extencive site, but nothing complicated.
PHP is a simple language, and has a lot of simularitys to DM. The biggest diffrence is that PHP is run at request, as to where DM is live action.
A good way to learn is to use the program EasyPHP. It has a preconfigured apache/php/mysql server in it. It is great, and easy to use. I am using it for testing of the site I am working on. I am still fumbling around with it, learning the ropes, but I have a good grasp on PHP and MySQL now. Http://codewalkers.com helped a lot. http://en.wikibooks.org/wiki/PHP could also be a great help, but I have not went though it very much.
I don't claim to be a PHP expert or anything, I have just learned the basics. With what I have learned, I could probably code something close to these blogs, believe it or not (not that I would try, why should I anyways).