It can definitely, and out of the box, control Keynote.
Then there are apps available that let you customize the remote's functions. Basically, whatever you can do with a key on the keyboard, you can then do with the remote. But you might lose its standard functionailty e.g. for Keynote, not sure though.
Google for such apps, but keep an eye on compatibility with your OS X version!
I have found an app called remote buddy express on the app store.
Does anyone have any experience of this app, I imagine I could configure this to control elements of browser behaviour that are influenced by the keyboard?
Or perhaps you know of an alternative that provides similar functions, ideally free?
Okay, I downloaded free 30 day trial of remote buddy express and it's great - parhaps even a little more than I was needing. This type of functionality, or at least a clearer indication of the need of an app like this to do certain things, should come included with the apple remote.
The full version costs £14 though, so I'm open to suggestions if anybody knows of any cheaper/free apps or ways to accomplish what I'm after.