For quite a number of years now, Japan has had a form of advertising that I found quite interesting - the huge advertising trucks that drive around in highly populated areas such as Shibuya, Shinjuku, Ginza and so on. In Japanese these are known as "Koukoku Torakku" [広告トラック] or literally "advertising truck"
Done a Google to check up the prices to discover that they cost more than I thought. For the ad in this photo which looks roughly like a 9.4 x 2.6 meter space - this will cost 2,600,000 yen (about 22000 USD at todays rate) for a week which includes production and blasting out of music as the truck drives around (with driver included). Prices are available on this site if you are interested ^^
There are other companies like this and this one which gives you more of an idea visually of what you are getting but they don't list any prices.
I've never seen this form of advertising in any other country but do admit that it does catch my eye. Anything like this in your neck of the woods?
The rest of this post are photos of when I spotted these trucks and had my camera handy enough to whip out and snap em before they drove off. Most of these taken in Shibuya with a couple in Akihabara at the end.