I know that the ability to put an image on a tag is one way that SO does advertising, but what about open source projects that don't have a commercial sponsor? Would it be possible to allow images to be placed on tags for open-source projects?
For example the Ruby language is open-source, and it has a nice little logo (a ruby, ) that would look rather nice on the ruby tag for related questions. Is this something that could be allowed, or are you reserving this as a special perk available only for advertisers?