Bloip! Tarantino

Geek humour often revolves around the principle of comedy through futility: the fact that someone has spent days of their life in the pursuit of a goal which is utterly arcane to functioning social humans, and the fact that this process is laid transparent by the product of their labours, is the joke.

Take this (via Joystiq) for example. It's a fight scene from Kill Bill dubbed with Mario sounds. The video isn't funny, but the unswerving dedication of the creator to his initial aim of geting those darn sounds in at every possible opportunity is what you're really laughing at.