1. A user-interface method for selecting a subset of items from a relatively large set of items in response to search criteria including ambiguous keystrokes entered by a user from a keypad with overloaded keys and including unambiguous metadata associated with a previously selected search result, the method comprising: a. receiving ambiguous keystrokes entered by a user from a keypad with overloaded keys in which a given key is in fixed association with a plurality of alphabetical and numerical symbols, wherein the user is using the symbols to search for desired items; b. in response to receiving the ambiguous keystrokes, selecting and presenting a first subset of items and corresponding unambiguous metadata associated with the items presented based on the ambiguous keystrokes; c. receiving a selection of one of the items of the first subset of items from the user; d. in response to a locking operation received from the user, locking in fixed relation at least one of the ambiguous keystrokes to at least one unambiguous metadata term associated with the selected item; e. subsequent to receiving the locking operation, selecting and presenting a second subset of items based at least in part on the locked unambiguous metadata term; and f. presenting the second subset of items.