http://www.searchingformyspermdonorfather.org/
This website was set up in an attempt to assist any donor offspring in locating their donor father. Each offspring has their own subpage with details about themselves so that anyone who is a donor or someone who has info that may be of interest can determine if there is a possible match and have means of contacting these individuals.
(Please bear in mind that any offspring may not necessarily look like their donor father)