Prepaid gasoline

If you're running a gas station, this idea's for you.

Build a website that updates your advertised price of gasoline in near real time. Allow customers to prepay for a limited amount (up to say 50-80 gallons) of gasoline, redeemable within a limited amount of time (up to say 60-180 days).

Customers will watch your site to catch a good price, which allows you to see internet traffic, advertise, show deals, promote your brand etc. Customers will prepay for gasoline when the price is right, giving you an upfront payment, while allowing you to undercut the local competition. If they're buying from you, they're not buying from them. This does mean that you're not selling as much gas at peak prices, but it also means that neither are your competitors. You can support lower margins by moving more product, and supplementing the loss with advertising, brand loyalty, and sales of other products.

Walmart shopper

Build a website that allows a customer to enter a grocery list, a local address, and a preferred delivery time. Access this list with a smartphone, do the shopping for the customer, charge a 10%-20% fee of the total grocery cost, and a $10-$20 delivery fee based on distance to the address.

So, if you charged 15% and a $15 delivery fee, you could knock out the grocery run in about half an hour to an hour, depending on your shopping savvy and traffic, which means you could easily make $30/hour. That's $60,000 a year.

This number grows rapidly as you get better and/or hire out the shopping and delivery.