Agile documentation - easy but important?

I've just been working on some enhancements to my free Lotus Notes application SDMS - a Simple Document Management System (also available here). Being a good little boy, have been finishing off my efforts by documenting the new features.

And by serendipity I've just been reading a new article by Scott Ambler, and it seems to make sense so I recommend it to you:

Agile Documentation Strategies ... It's not as hard — but more important — than you think.

And while you're at it, read more by Scott Ambler, such as Examining the Big Requirements Up Front (BRUF) Approach in which he argues that

BRUF leads to significant wastage, that an evolutionary approach to development is must less financially risky than serial development, and that you should take an agile approach to requirements.