davidlim88,
I just actually recorded some accoustic tracks tonight with the nt1000. I would like to tell you that I used some unique placement to get the perfect sound, but that just isn't the case.
I had the mic 10-12 inches from the guitar at the point were the neck joins the body and turned slightly towards the 11th fret.
I tried other positions, but kept comming back to this. Every guitar is different, but for my martin this works extremily well. The guy I was recording was very impressed and kept bringing up the sound of the accoustic all evening.