Yes, that's true - shooting macro doesn't mean that the subject needs to be glued to the lens. Even dedicated macro lenses usually need 8-10 cm from the tip of the lens.

Taken from Wikipedia:
The classical definition is that the image projected on the "film plane" (i.e., film or a digital sensor) is close to the same size as the subject.

So macro has nothing to do with the distance to the subject. You can be 3 feet away and still shoot macro with the proper lens (say 300 mm).

But I digress. The minimum focus distance on the N900 is quite decent, there's nothing to worry about it.