1. A computer-implemented method for substantially simultaneously creating two or more modified designs, the method comprising: providing two or more designs for simultaneous displaying to a reviewer, each design having a plurality of design components, providing at least one control adapted to allow the reviewer to manually select a preference level for at least some of the design components in the designs, receiving preference levels selected by the reviewer, generating two or more modified designs substantially simultaneously in accordance with the received preference levels, and providing the modified designs for displaying to the reviewer.