I'm creating a SYSTEM for PHP, and I can't figure this thing out.

Language: PHP & MySQL
Email: viralsmack@gmail.com
Description:

I'm creating a System for PHP, in which a user can submit his own "pages" to my website. He/She registers, Logs in, and then, has an option to create their own page.

Now, here is what I need help on:

I want it so the user can link their page to others, easily.

So, in that case, it has to be a Directory. Such as: mydomain.com/pages/bob

That way, he/she can show his friends his page, by memory. (instead of .php?id=3423423)

Any Help on creating DIRECTORIES in php, and putting an "index.php" in them?