The November 1 issue of Library Journal has a great article about what Academic Libraries are doing to draw in first year students. Some of the tips would be applicable to public libraries as well.
MIT used a puzzle advertising campaign (drawing on its reputation as home to the oldest and largest puzzle hunts in the country). University of Illinois Undergraduate Library is using Twitter to reach users and Penssylvania State University Libraries used interatctive games instead of the traditional open house to introduce students to the library. Read the full article here.