Of all magic in PHP I probably like the __autoload() hook the most. It saves a good deal of tedious script inclusion calls and may drastically speed up your application by saving the parser from doing unnecessary work. Allthough it has been around since the release of PHP5, I haven't found any convincing applications for it yet.
He notes that there are drawbacks to its current usage (with an example of dynamic class loading) - namely directory and naming issues - and suggests a "class finder" to help work out the kinks. He, of course, gives his simple code for a "Smart loader" class to do the hard work for you...
