Builder.com.au has a new article today about the recent image issue - the PHP code embedded inside the GIF - that's come up on several sites.

The exploit code slipped through the site's defenses with the aid of a legitimate image at the beginning of the file, according to a blog post on the Sans Institutes's Internet Storm Center. [...] Malicious attackers planted PHP coded exploit script within an image file. PHP is often used as a programming language to create dynamic Web sites.

The article reports that, while this exploit hasn't happened much, the occurrences of it's use are growing with victims in a wide range of classifications - from small personal sites out to a certain major image hosting site. This same issue was discussed here on the PHPClasses.org website as well.