One thing that PHP has lacked that many people have tried to assign is a logo or a character that people can identify with PHP. There's been some interesting contributions, but the one that seems to be coming out on top is the elephant created over in France in cooperation with the PHPInfo.net website.

One of their latest news stories states: The elephant image, created as an illustration for some of the French-speaking PHP sites, is on the way to becoming an official logo of PHP the in the rest of the PHP world. It shows up on Rasmus Lerdorf's site, (creator of the PHP), as well as in the one of the first issues of the PHP Journal, and today, is a logo of PHPCon 2002.
(translated)

In case you've never seen this elephant that they're talking about, hop on over to PHPInfo.net and check out the file formats that they have posted: Illustrator, EPS, Gimp, and the good old standby, Photoshop - as well as a great example on Vince's main site.