I would just like to make a point that may or may not influence someones decision in what lens to buy. Adding extension tubes makes any lens they are attatched to, become less user friendly, basically you lose infinity focus and you have a very narrow focus field which varies depending on the lens used. It can be pretty frustrating when taking a tiny mini beast with an extension tube on, then spotting a butterfly posing and having to remove the tube before attempting the butterfly.
Here`s a question I would like to throw in:
At what point does close-up become macro?
Is it 1:2 as Fuji suggest with their 60mm? Is it 1:3 that Milandros friend says that Pentax have used? Is it 1:5 that Canikon use with some of their lower priced zooms? Or something completely different.
I`m guessing that lens manufacturers put macro on some lenses is that it sounds better than "not quite macro but that`s all your getting"