eBay has changed the way the world shops.   Here's your chance to get in on this retail phenomenon--and it's simple and inexpensive to get started. All you need is a computer, a digital camera and products to sell--and you're well on your way to reaching eBay's $2 billion global marketplace.    You can sell almost anything on eBay, from the familiar to the exotic.    And you can do it any time of the day or night, making this a great business to start part time.Top 20 Low-Cost Homebased Businesses to Start.