In this post on his blog, Pierre points out a GD-related site that he's come across with articles, tutorials, and various information about graphics manipulation in PHP.

PHPGD.com is a resource for anyone interested in creating graphics and graphics applications using the programming language PHP with the GD or GD2 image library. PHP's GD library is based upon the original GD library by Thomas Boutell.

They already have several articles posted, including one covering black and white conversation and working with TrueType fonts in your images. There's only a few scripts posted so far, but there are tons of resources they can pull those in from. The "Discussion" area for the site points over to the DevNetwork forums, part of the same community board we share.