I think I saw a thread a few days or weeks ago asking about this, not sure if anyone had mentioned this and I am too lazy to search today, so here goes:
http://www.blueechosolutions.com/hd-ez-lock.php
Not exactly cheap at $20 a pair, but I don't think I will need them for all of my gear, just the one on my TV where the plug sees the most strain. Available in Jan. Attaches to your gear and holds the cable in place.