1. A user-interface system for incrementally finding and presenting one or more content items in response to keystrokes entered by a user on an input device having a known layout of overloaded keys selected from a set of key layouts, each overloaded key having a corresponding set of alphanumeric symbols, the system comprising: a database stored in an electronically readable medium, the database containing content items and corresponding descriptive terms that characterize the content items; input logic for receiving keystrokes from the user and building a string corresponding to incremental entries by the user, each item in the string having the set of alphanumeric symbols associated with a corresponding keystroke; mapping logic, cooperating with the database, to map the string to the database to find the most likely content items corresponding to the incremental entries, the mapping logic operating in accordance with a defined error model, the error model corresponding to the known layout of overloaded keys of the input device; and presentation logic for ordering the most likely content items identified by the mapping logic and for presenting on a display device the most likely content items in accordance with defined ordering criteria; such that the user-interface system receives ambiguous entries from the user and presents the most likely matching content items.