Portal Turrent Gas Mask
I never thought people were than bothered by gas masks, apparently I was wrong. Not supprising when people create gas masks to make you look like a portal turret. Via [Kotaku]
Aperture Science Gas Mask
The Portal continual testing initiative had some great quotes from Johnson, one of which is loosely related to this bit of craft: I did say loosely. Very loosely. Via [io9]