http://www.cyberpump.com
If you haven't used HIT yet, try it. You will be amazed. If you're using HIT now, you may just need a different way of utilizing it. Without knowing what you're doing specifically now, I can't recommend much else. People who make good gains on volume and then plateau usually find HIT to be pretty cool.
Ever tried 20-rep squats? You don't want to try it without a good spot or a cage, but if you were squatting without those, shame on you anyway! Just load a bit lighter than usual and then do 20 full, deep squats. Rack the weight and add the smallest increment you can the next week. 5 lbs is actually at the high end of the increase you want to make here. Good luck. It's about time I kicked my own ass back into high gear too. Maybe you and I should do a little informal competition, although I'm so undertrained right now I'll probably gain fast for at least a few weeks.