Well, I've just spent the past 2 hours replacing my plugs. Not as difficult as I have heard it can be, but still not something I'd like to have to do too often. Especially when the plugs are NZ$30 each. :-P
The car does seem a little smoother with the new ones though. I'll see if it has any noticeable effect on fuel consumption.
I don't know when (or if) they were last replaced, so thought it'd be due seeing as the car's done 95,000km. Glad I did.