A place where normal people like you and me gather to buy and sell various stuff such as coins, stamps, weapons, animals, porn videos and overpriced computer equipment. Flea markets are the gathering places of freakish people (much like E3, MacWorld, Comdex, any trekkie convention). And they are one of the very few places you can find grownup-adults standing behind tables stuffed with beanie babies. Also a really great place to buy bootleg T-shirts (cant find any Chaigo Bsulls shirts at any local mall)

In Scandinavia they have a pretty good system of selling winter clothes at flea markets. People donate whatever they don't need to clothing stores, who then put them out in the street for general sale. You can get a sweater for ~25 kroner. Reusables are actually taken seriously, unlike in the U.S.