I just ordered 8 more on Monday. That'll put me at 12 in this system. I couldn't pass up 8GB of DDR3 1600 for 50 bucks. I OCCASIONALLY use up all 4 I have now, but I don't do a whole ton of actual work on this computer.
i7 860 - GA-P55-USB3 - 8GiB - HD7850 - SSD - 3.64TB HDD - Xonar D1 - U2410 - Win7 Pro x64.