A good place to store the pieces of your own code that you find useful and also to find other useful pieces that people have shared is a place called Snipplr.com
http://snipplr.com/
I have put several things on the site. They have a lot of good stuff. You can add these to your Code Library in Rapid PHP or whatever your using.
It would be nice if we could backup the entire Library into an XML file or something that we could move between computers or share with other users.