1. A method for conducting database searches by telephone, the method comprising: subdividing a master grammar set into multiple speech recognition grammars, each of which corresponds to a different sequence of N telephone keys; prompting a telephone user to enter N characters of a search query on a telephone keypad with one key selection per character, and detecting a resulting sequence of N telephone keys selected by the user; prompting the telephone user to say the search query, and receiving a resulting utterance from the user; and selecting the speech recognition grammar that corresponds to the sequence of N telephone keys selected by the telephone user, and using said speech recognition grammar to interpret the utterance; wherein the speech recognition grammar is selected without requiring the user to uniquely specify said N characters of the search query; wherein N is less than the number of characters of the search query as uttered by the user, such that the user does not enter all of the characters of the search query on the telephone keypad; wherein the method is performed by a computerized system that comprises one or more computing devices.