Here are 8 trendy people silhouettes in vector format (eps) for you to download for free. These are licensed under the creative commons. There are 2 eps files, 84 png files, 84 gif files and 1 png file at 300dpi. They are also at many different resolutions. The size is 1.1 Mb.

Source: http://dragonartz.wordpress.com/2008/05/02/vector-people-silhouettes-by-dragonart/