Just to give a bit more info, here are some links that might be useful to people new to GTD:
An overview of the idea and the 'GTD movement' itself: <a href="http://www.guardian.co.uk/technology/2005/sep/29/businesssense.businesssense" rel="nofollow" target="_blank">http://www.guardian.co.uk/technology/2005/sep/29/businesssense.businesssense</a>
And a ton of links to explore different aspects in greater detail:
And from the man himself: <a href="http://www.davidco.com/" rel="nofollow" target="_blank">http://www.davidco.com/</a>
Personally speaking, I don't really get GTD. It seems like an awful lot of work to put in to organising yourself, and as such would only add to your workload. That said, I haven't tried it. One thing I really liked the sound of though was having a 'sometime maybe' list for the things you really want to do, but realistically may not get round to. It's a good way of keeping them out of the way but not dropping them completely.