When I first saw this Trend Forecast map mimicking a weather forecast, it provided a good demonstration of how images can be more informative than words.
I have no idea where the data was taken from, or whether it was just intended as a cartoon, but either way, it made me wonder what a world map would look like if Trend Hunter made the same type of map. I suppose you could base it off of web traffic data or submission locations and have those count as degrees of trendiness.
Trend Forecast Maps
More Stats +/-
Buzz Marketing's 2007 Trend Forecast
Presidential Weather Predictors
Making Hurricanes Obsolete
Style File Forecast