TOP TEN INTERNET FADS
According to an article in Kuro5hin blog:
A fad, for purposes of this article, is an idea or technology which is briefly popular, but can't outlast its own novelty value. Once people get over the newness of it all, there isn't really anything special left.
It lists the top ten internet fads of recent time. They include:
9. Flash Mobs
2. Anything sold online (eg. ebay)
Go read the dicussions for and against the list here.