This is a term for two people sharing ear buds, like conjoined twins, so that they can listen to the same iPod or other mp3 listening device. It is a little pejorative in that "twod" has a pronunciation that is closer to "twat" than "two". It can refer to douche-bags who are blocking your way because they are doing this. It can also refer to two people doing this in a sweet and "cutesie" manner, as when couples do it.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.