From the WebCheatSheet.com site, there's a new tutorial helping you create some dynamic images for your pages, specifically creating a CAPTCHA image, a dynamic bar graph, and using these images on other pages.

They assume you know a little something about the graphics functionality in PHP before you've started because they dive right into the code for the CAPTCHA image. They explain what the code's doing, but if you're not familiar with the PHP GD functions, you might be a little lost. Their string for the image is a randomly generated md5 hash.

The bar graph example is similar and they include a bit more for it - pulling information from a database (MySQL) backend (the results from a poll). They provide all of the code for this example and finish the tutorial off with a brief look at the options for using these types of dynamic images on the other pages in your site.