8. A computer-implemented system comprising: one or more computers; one or more data storage devices coupled to the one or more computers and storing instructions that, when executed by the one or more computers, cause the one or more computers to perform operations comprising: while receiving a text input entered into a search engine query input field by a user, the query input field displayed in a map user interface having a viewport displaying a portion of a map at a particular zoom level, and before the user has submitted the text input as a search query to a search engine: determining the particular zoom level and a geographical location associated with the portion of the map displayed in the viewport at the particular zoom level; obtaining a plurality of query suggestions based at least in part on the received text input; grouping at least some of the query suggestions based on a common primary query term shared by the query suggestions, wherein the grouped query suggestions include one or more refinement terms that refine the common primary query term, wherein the one or more refinement terms that refine the common primary query term are selected based, at least in part, on the particular zoom level of the map as presented in the viewport while the text input is being received, and the geographical location displayed in the viewport while the text input is being received; and transmitting a set of the plurality of query suggestions to a client device for presentation to the user, wherein the set includes the grouped query suggestions that are presented as a group with the common primary query term presented in a prominent position and the one or more refinement terms presented in subordinate positions relative to the common primary query term and wherein the common primary query term and the one or more refinement terms are each user-selectable.
8. A computer-implemented system comprising: one or more computers; one or more data storage devices coupled to the one or more computers and storing instructions that, when executed by the one or more computers, cause the one or more computers to perform operations comprising: while receiving a text input entered into a search engine query input field by a user, the query input field displayed in a map user interface having a viewport displaying a portion of a map at a particular zoom level, and before the user has submitted the text input as a search query to a search engine: determining the particular zoom level and a geographical location associated with the portion of the map displayed in the viewport at the particular zoom level; obtaining a plurality of query suggestions based at least in part on the received text input; grouping at least some of the query suggestions based on a common primary query term shared by the query suggestions, wherein the grouped query suggestions include one or more refinement terms that refine the common primary query term, wherein the one or more refinement terms that refine the common primary query term are selected based, at least in part, on the particular zoom level of the map as presented in the viewport while the text input is being received, and the geographical location displayed in the viewport while the text input is being received; and transmitting a set of the plurality of query suggestions to a client device for presentation to the user, wherein the set includes the grouped query suggestions that are presented as a group with the common primary query term presented in a prominent position and the one or more refinement terms presented in subordinate positions relative to the common primary query term and wherein the common primary query term and the one or more refinement terms are each user-selectable. 9. The computer-implemented system of claim 8 , wherein the received text input does not comprise a complete word and the common primary query term comprises a suggested word completion of the received text input.