On PHPBuilder.com today, there's a new article that's sole purpose is to guide you through using SQLite with PHP4.

There is a great misconception that SQLite is not available for PHP4, rather only for PHP5. In fact, SQLite support has been around for quite some time courtesy of the bindings available via the PHP Extension Community Library (PECL). This tutorial is intended to show you how to install the SQLite PECL Extension in PHP4. Following it's installation I will walk you through a basic example of using SQLite to access a database stored in a flat file.

The article continues on, talking about what SQLite is, its advantages, as well as how to configure, load the module and test the installation. With SQLite being so easy and light to use, it's definitely a welcome addition to the PHP family (plus, it works all over the place - not just in PHP).