I know Leslie talked about this too, but it deserves further discussion. I think embassy visits are PD efforts, however, since a lot of embassies are participating, they may not get the due credit. For example, I went with a Malaysian friend today to check out the Malaysian embassy, which had it's open house today, along with a bunch of others. So, today, I checked out not only this embassy, but also the Pakistani, Nigerian, Bangladeshi, and Ethiopian embassies.
Since the Passport DC event is so huge, (check out the website to see what was happening today: http://www.culturaltourismdc.org/calendar2532/calendar_show.htm?doc_id=76354) I think it drew attention away from events that would have been more informative. Also, it kinda made people compare countries, that would never be compared, just based on what their embassy event was like. Although, some may argue that these countries may never have gotten this attention had it not been for an event like this.
I think I was most impressed, from a PD perspective, with the Bangladeshi Embassy- this is because they greeted you politely; and by they, I mean a woman saying "Welcome to the Bangladeshi embassy, here is our Ambassador", who then shook your hand- even with the possibility of catching the swine flu! Additionally, there were people standing behind the ambassador handing out surveys about your experience at the embassy, what you already know about Bangladesh, and how you developed your opinion, of the country. Albeit there were many of these surveys that people did not bother to fill out, however there was a decent-sized box by the door full of people's precious opinions. This is information that is hard to get, and this was the only embassy that I visited that was doing it. Kudos Bangladesh!