I saw this tweet tonight about a gun she found and I immediately booted up the game to go get it. This is the coolest gun I've seen so far and I actually thought it was a fake video at first. It's definitely an MS Word Clippy reference.
I also discovered the GLaDOS (actual voice and cake reference) mission tonight. I wonder how they worked that out with Valve and I'm wondering what other stuff like that is hidden away on the map. Yea I know Portal cake jokes are lame now, but I was surprised by it at least.
Anyone discover other guns that do unique things like that or any other game references?