advertising for bitcoin through newspaper, radio, subway billboards
I can't imagine an approach that would give less bang for the bitcoin, except maybe sending them to
[Edit, don't send bitcoins there -- they disappear.]
I think this can be a good idea to improve visibility to increase its demand.
In the past 24 hours, I got timeouts trying to use Bitcoin's most popular eWallet and I got a "sorry this site isn't important enough for us to fix it right now" message for one of the most popular Bitcoin web sites.
I don't know that promoting to the masses would be something that helps anyone, at this point.