This is a simple function that resizes and image using the GD add on for PHP.
Just a disclaimer: I know its not perfect, but i figured i would post it because the only other one on here is way confusing to some new PHP developers. Hopefully this one will help you learn how to use GD, and then you can write a better one.

I needed to send an email through an authenticated SMTP server. I found the snippet on the PHP website to do the trick.

Generate a random number or string in PHP.

This function is useful in helping to deter spam bots by obfuscating things such as e-mail addresses and URLs that are displayed on a web page. While it's not 100% fool proof, it does offer some protection.

Example:
$email = html_entitize('foo@baz.org');
/*
Outputs foo@baz.com
*/

Generates select boxes, text boxes, check boxes and radio buttons. Via a handful of functions.

This is a class for generating HTML tables. It's kind of rough, but I thought somebody might want to do something with it.

Here's a little snippet I got from SitePoint that I now use all the time. Add the code below to the start of each script.

Basically, what this does is checks to see if magic_quotes_gpc() is enabled on the server, and if it is, then it gets rid of all the slashes that magic_quotes_gpc() adds to input from $_GET, $_POST and $_COOKIES globals.

It's a good snippet to use, because it negates the bad programming practices that having magic_quotes_gpc() lets you get away with, and means that you don't really on PHP to validate your input; you get to do it all yourself ;-)

Over the summer, I worked on a project in which I needed to parse logfiles which were in the following format:

IP|USE|TIME>IP2|USE2|TIME2>

and so on.

When I parsed them to display the log file in a user-friendly fashion, I used the following code:

Here is an easy calendar!

Hope you like it dude =)

With this function you can calculate the age of a person

Example:
echo "Age is: " . age("1984-07-05");

Result will be (23 Feb 2005) = "Age is: 20"