Bartering is as old as the ancient agora of Athens, when currency took many forms (okay, I had to get that ethnic plug in somewhere).

FORBES: Bartering for Survival - Have I Got A Deal for You

Marketplaces, be they Ebay (nasdaq: EBAY - news - people ), the New York Stock Exchange, a Middle Eastern souk or an ancient agora, share a common characteristic: They are forums that bring together buyers and sellers.

FORBES: Why the world would be better off with one big stock market.

It somehow reminds me ... of something in ancient Greece, the agora, the marketplace.

NPR: Welcome To The Twitterverse

The traditional town meeting has its roots in the agora of ancient Athens, a place for sober, if contentious, deliberation.

CNN: Essay: Ye Olde Town Gimmick