Just because the world as we know it has come to an end doesn't mean that people won't want to read an amusing limerick written on a bathroom stall. And for just under £5, this Pocket Shark Tactical Marker is guaranteed to survive almost anything—from a Mad Max-style dystopia, to even a zombie uprising. Let's see your Sharpie do that.
The Pocket Shark's secret weapon is that it's made from high-impact plastic that's four times as thick as the stuff you'll find on lesser markers. So you can smash it with a hammer, drive over it, or even incapacitate whoever's trying to stop you from adding hilarious moustaches to people on bus shelter ads. Furthermore, the Pocket Shark's cap screws on so there's little chance of it accidentally drying out, because if you thought gas was hard to come by during the apocalypse, try finding black ink anywhere. [ThinkGeek]