http://xyne.archlinux.ca/info/powerpill
I just can't believe how I missed this great pacman addon. (love the name.. btw)
Just installed powerpill. Edited /etc/yaourtrc and set PacmanBin to /usr/bin/powerpill. Then set ADDITIONAL_POWERPILL_ARGUMENTS to --nomessages in ~/.config/powerpill/powerpill.conf. I can't even notice it exists but package downloads from Arch mirrors is now using my full bandwidth. Simply awesome. Another reason to stick with Arch. :)