Well, cash is doomed. Advancements in web-based technology & 3-G make it easy for individuals and small businesses to take credit card (and debit card) payments using the iPhone. This frees up vendors to take their business on the road easier, such as taking a transaction at a trade show or doing a deal at the spur of the moment at a meeting. With the ease that Apple retail store agents assist customers by ringing up transactions on the floor, many small business owners will be able to adapt similar processes and make shopping more customer friendly.
There are a number of companies that have developed small credit card scanners that plug into cellphones and for a small fee will process transactions on the spot. Paypal developed an iPhone app that allows a "bump" type transaction. (Source: www.paypal.com/mobile) The Paypal mobile app boasts security while ease of use--vendors are simply required to take the customer's email address or phone number to validate the online transaction.
Another innovator in iPhone (mobile) transactions comes from a founder of Twitter. The company is called Square and allows users to take credit card transactions from either an iPhone or an iPad.
