Via Google (click on "add more content" to your iGoogle page), I discovered Funny Ads. I've had it on my iGoogle page for a few days, but didn't watch any of them until today. A number are in languages other than English (some of those have English subtitles), and a number are "silent", where the pictures tell the whole story.
Humour is an element common to all those I saw at a quick glance, and I think they would be great for teaching English, e.g. as prompts for a writing assignment (write the story you saw, create your own ad), or a speaking task (tell your partner what you saw; what is the ad for? Do you think it's an effective ad? Why/why not?), or a multimedia project (create your own ad, video it, upload to Internet).
My favourite is the Deutsche Postbank one.