Would you want to plan your own funeral?

A website that allows people to plan their own funerals... good idea or bad? 

The man behind Once I've Gone set up the website following the deaths of his mother and sister, when he realised that he had no idea what they wanted to happen at their funerals.  John Dibbs insists that the website isn't morbid, 'but practical and light hearted, allowing people to leave messages for people they love'.

I don't have a problem with the idea.  I've already told my nearest and dearest that I want one of those eco-friendly wicker or cardboard coffins (caskets, if you're in the US).  I really don't want people shelling out their (or my!) hard-earned money for a top-of-the-range job that's immediately going to be burnt in a fiery furnace, and I have one or two ideas about the words that are said over me and the music I'd like to have played.  Come to think of it, I've hammered it into them for years that I want any or all of my organs to be donated to anyone who can use them, so I suppose, in a way, I have already more or less planned that final stage of my life, haven't I? 

What about you?  Would you plan your own funeral or do you just prefer not to think about it at all?