I'm an independent, third-party developer for VALVe's Source engine, with specific emphasis on developing for Portal with a pinch of Half-Life 2. My current undertaking is a full-scale mod entitled Portal: Stay Inside.
This is a small map demonstrating my implementation of the Pneumatic Diversity Vent ("objects...are identified but never judged!") mechanic seen in Portal 2 previews. It's still a bit buggy and hard as HECK to set up, so I probably won't do much with it, but it's a neat effect anyhow. It's not the prettiest level, but I was focusing more on making the mechanic work.
Another one who does that.
Anyway, nice work.
Yeah, I know it's a concept that's been done to death, but I figured I'd toss my hat into the ring and test my mapping skills.