selling small things or small amounts, often using digital Currency Systems

• http://www.peppercoin.com/
• http://paypal.com
• http://www.bitpass.com/

the case for miocropayments circa 1998 [link] and the case against circa 2000 [link]

• http://www.useit.com/alertbox/980125.html
• http://www.openp2p.com/pub/a/p2p/2000/12/19/micropayments.html