/etc/apt/sources.list:

deb http://rous.wpi.edu/debian/ testing main contrib non-free
deb-src http://rous.wpi.edu/debian/ testing main contrib non-free

deb http://security.debian.org/ testing/updates main contrib non-free
deb-src http://security.debian.org/ testing/updates main contrib non-free

deb http://deb.opera.com/opera/ testing non-free

# deb http://download.videolan.org/pub/videolan/debian sid main
# deb-src http://download.videolan.org/pub/videolan/debian sid main

deb http://rous.wpi.edu/debian/ unstable main contrib non-free
deb-src http://rous.wpi.edu/debian/ unstable main contrib non-free

/etc/apt/preferences:
Package: *
Pin: release a=testing
Pin-Priority: 650

Package: *
Pin: release a=unstable
Pin-Priority: 600