1. A computer-implemented method of discovering items associated with particular contexts, the comprising: outputting, for presentation to each of a plurality of users, a context-specific list of items in which each of a plurality of items on the list is presented together with a respective control for initiating a display of similar items, said context-specific list corresponding to a particular context, said particular context being one of a plurality of defined contexts in which items are capable of being displayed; recording, in association with the particular context, user activity associated with user selections of the controls for initiating displays of similar items, said user activity including user selections of particular similar items, wherein recording said user activity comprises recording an indication that said user selections of similar items were made in association with said user selections of the controls for initiating displays of similar items; and determining whether the recorded user activity associated with a similar item is sufficient to add the similar item to the context-specific list, said determining comprising calculating a weight value for the similar item, and using the weight value to determine whether to add the similar item to the context-specific list, said weight value revealing a degree to which the similar item is associated with the particular context; said method performed by one or more computers of a multi-user interactive system.