Running audio wire in office, wall or ceiling location?
Placement of speakers for a surround sound system can get very specific if you care about it.

By far the most important speakers are the front 3 (center, left and right). The center channel is the most important for movies because most of the dialog comes from the center speaker. Left/right speakers are more important for music but still used a lot in movies.

Ideally all 3 of those speakers would be at the same height and lined up as close as possible with the height of the screen. That means putting the center speaker directly above or directly below the screen, and the left/right accordingly.

Also, ideally the left and right speakers should be about 30º to the side of the center speaker. The exact distance will depend on the position of the seats.

Rear speakers are used mainly for ambient affects and are not nearly as important. I think ideally they are mounted slightly above ear level and 100º to the side of the center (i.e. more to the side of the listener than behind), but ceiling mounting is probably fine as well.

So as you can see you do not want the speakers "equally spaced", although there may be some benefit to wiring your room that way if you want flexibility about future layout.

A few other things to note:


If you are using an AV receiver to process the surround sound, many of the mid- and high-end units include room calibration modes that let you compensate somewhat for oddly-placed speakers.
If you are going to be using a computer to play movies, note that getting surround sound out of a computer can be tricky. Even for computers/sound cards that support surround sound, it's not always as easy as it seems like it should be.