Cash, credit or iPhone app?
One of the greatest uses of the Internet is commerce.
Aside from exchanging information like never before, many discovered how the web could change the exchange of goods and services.
Amazon.com began selling books and CDs, but expanded quickly into everything else. You can even have groceries delivered to your door through the company's website, at regular scheduled intervals.
eBay.com allowed anyone to buy anything in the largest continuous garage sale in history. Need to buy or sell Time magazines from the 1940s? A car? A whole palette of paperclips? A decommissioned nuclear missile s...