I'm setting up my first home theatre (42" Sammy plasma, Energy's 5.1 Take Classic speakers, Yamaha HTR-6140B AVR - I can't wait 'till I can have a sig so I don't have to type it up every time. :P), and trying to decide how to place my speakers. I've got large DVD shelf towers on either side of the screen that I'm planning on putting the front speakers on (the shelf backing is just paperboard, so it shouldn't cause as many problems as a bookshelf placement usually would), and the center will easily fit on the front of the TV stand, but it looks like the only option for the rears is wall-mounting.

Any suggestions on a decent set of wall mounts for the two rear speakers that won't put too much strain on my wallet? Under $50 would be best, but if I eat Kraft Dinner for a week I can probably swing up to $100 (taxes in) if it's absolutely necessary.