Here's where I keep all of the classes I use on a regular basis in my php programming, mainly to keep myself from reinventing the wheel.
Classes included so far:
template.class.php - this one is my attempt at a simple template engine. db.class.php - this is used to connect to a db. right now it's only set for MySQL, but I may include PostgreSQL as well.
All of these classes have been sanitized for the public's use. Meaning, I've removed passwords and urls that I wish to keep private.