I was talking with my sheet rock guys this weekend and one guy who seemed like he has worked on HT's in the past said I should use Window plugs. Anyone tried this? He said you get some kind of Styrofoam or such and cut it perfectly in the shape of the window and "plug" it up when you are watching movies for sound and light reasons. My plan had been really thick curtains that my wife will be making soon. Anyone seen a good how to thread or such?

You mean like this??? I plugged this window in my equipment "service chase".

http://i92.photobucket.com/albums/l27/verrot/Home%20Theater/P5280049.jpg

I have another "plug" behind this sound panel out in the main HT room as well. I took this picture at about 2:00 pm,,, this window faces North. (ZERO light enters the room)

http://i92.photobucket.com/albums/l27/verrot/Home%20Theater/P5181258.jpg

If you have a problem with keeping sound in or out a well made plug can resemble a soundproofed wall that fits tightly in the window opening.

If all you need to do is control light, back out shades and curtains should be just fine.

A styrofoam plug will work in keeping the light out but won't do diddly for the sound.

I was talking with my sheet rock guys this weekend and one guy who seemed like he has worked on HT's in the past said I should use Window plugs. Anyone tried this? He said you get some kind of Styrofoam or such and cut it perfectly in the shape of the window and "plug" it up when you are watching movies for sound and light reasons. My plan had been really thick curtains that my wife will be making soon. Anyone seen a good how to thread or such?

I did something like this (http://tomdufresne.com/v-web/gallery/album03/theater08_060002). I used styrofoam plug and MDF; two layers for sound minimization.

The plug is placed up against the window in a way to prevent rattles and provide a sound barrier to the outside. I beleive the two layers of MDF help with sound control, but probably don't completely stifle it.
Best,
Tom