Cover photograph (Copyright © 2005, American Society for Microbiology. All Rights Reserved.): Rhamnolipid surfactants modulate the distinct tendril patterns formed by Pseudomonas aeruginosa swarming across semisolid medium. The image shows the outline of the swarming pattern formed by the wild-type P. aeruginosa strain PA14 against a false-color background. (See related article on page 7351.)