Windbelt For Water

Adapt this to use floats that move up/down on stream water.

... a Windbelt, is a taut membrane fitted with a pair of magnets that oscillate between metal coils. Prototypes have generated 40 milliwatts in 10-mph slivers of wind, making his device 10 to 30 times as efficient as the best microturbines. Frayne envisions the Windbelt costing a few dollars ...

Priced In Gold

Website overlay or browser toolbar/add-on that automatically converts online store prices to the number of ounces/grams. For amazon.com, it would display the price in ounces of silver or grams of gold.

Unlikely to make any revenue.

Merchant Processing (VISA, MC)

Mobile payment processing startups are appearing. They can roll their own back office, or partner with visa/mc/paypal.

http://www.forbes.com/forbes/2010/1025/technology-mobile-payments-cellphones-fraud-visa-calling_2.html
Bling Nation, a Palo Alto startup that is building an alternative payment system that would bypass Visa entirely. Bling says that by starting with a clean technology slate it can charge merchants half or less of what they pay now. But a major challenge for Bling--or anyone trying to build a payment network from scratch--is that it must first persuade thousands of merchants to buy or rent yet another terminal to sit next to the one they now use for Visa and MasterCard.