Fred, I dug that post to the max, I'm still laughing ("hair guitarist !
). Brilliant and I agree with it pretty much but the question was about the acoustic guitar. That said, I'm going to nick all of these suggestions that the posters have put forth and try them out in various scenarios coz most inventive musicians are subtle and secret thieves !
heh, glad you liked my humor - not everyone does.
There are a lot of ways to mic an acoustic instrument aside from the obvious - pointing a mic at the sound hole of the instrument.
Others have suggested multiple mics - great suggestion.
Some suggested a stereo mic - also a great suggestion.
Omni for more ambience, cardioid for more instrument.
I personally always try to mic the back of wood-based instrument as well for additional options - the back of the instrument often times will give you a more bassy tone that can be mixed in, assuming the instrument is "decent" or better and not constructed of "rotwood" as so many knockoffs are these days.
A really "neat" method of recording just about any acoustical instrument is using a plate mic - I know radio shack discontinued them years ago but for $50 they were awesome little mics, and with basic hand tools you could remove the 6" square metal plate and replace it with a 12-18" square piece of 1/4" acrylic - mic your show, band, or what have you from the front and not obstruct the audience's view very much. They were also very useful for micing very large drum kits (typical of the 80's hair era where there is no excess in anything), large choirs, even micing audience feedback and response while close-mic'ing the musicians or performers on stage.
The only drawback is they sucked batteries like they were free. Other than that, they're one piezo-based device I actually like - they solve a lot of problems, especially in live venues.
There really is no wrong way to mic an acoustic instrument, or a guitar specifically, but start with the sound hole and work your way out. There is absolutely nothing wrong with using several mics, feeding them to different channels, and ignoring them later if you don't like the results.
Hope that helps.