Autoload can be used for at least one really cool thing. Proxy objects. For instance, if you have a pattern to how you code calls to methods/functions that do db calls, say, selectXXX for selects, insertXXXX for inserts, and you want to track how a particular object/package gets treated, proxy it around an autoloader.

1. Create an autoloader.
2. Regexp against the method name.
3. If the regexp matches, do something.
4. Call the original function.

Another pattern, is if you do any setXXX type things, write it out to the db. Now mind you, this may be quite sub optimial, but there have been instances where it is useful. Such that, if you have a UI, and someone changes the data, you dont' have to have the UI invoke something to save, but the proxy object would save automagically. It, in some ways, make your API a little more user friendly.. but it can and will take a performance hit if not done properly. Write through cache or something may be of use in that instance.