I've been helped by them before and it can be reassuring to have someone who knows the right things tell you that although you are horribly ill, you aren't in a state where you need to panic.  Equally when you can't get in to see a GP or you have one that doesn't want to listen to anything you say, you can get useful information from NHS Direct.

Personally I don't know if that is a good enough use of money in itself.  Is NHS Direct linked to out of hours GP/Dental services?

Ad astra per aspera