From the DatabaseJournal site, there's a piece about planning for the future in your code, and implementing one of the most popular database classes as an interface - An introduction to the ADOdb class library for PHP.

In this piece, they tell you why you should use something like a database class in your code, and how to get the ADOdb class all set up and working. They even go so far as to show you how to connect, insert, delete, and update your database with the class so you'll get a good idea of how to use it.

I think, personally, that a good, standard database class used all over the place can keep most of the code out ther a bit more well-maintained. So many people use their own custom interface, but lots of confusion could be solved with a more standard approach.

Thanks to PHPBuilder for the link...