Easter Eggs/Glitches:

Here are some Easter Eggs I found:

There is a sign in the Subway that says "Orange Box Juice"...wonder what that is referring to??? :)

There is a Team Fortress "Collect all 10!" cereal box, which some believe could mean Valve will be adding in another character in TF2.

Really...that's all there is that I can find so far. There was a glitch while in NoClip mode where your teamates (if in Single Player) would spawn below you, and at one point, everyone died except Louis, and he was walking on nothing, but 4 feet below him was a mirrored version of him...weird huh?