Here are a few great ways to make some quick cash on the internet:
Sell all your old books, music and movies on Half.com. It's affiliated with Ebay, and your user ID for Half.com can also be used for Ebay. I use Half.com myself, and there's no easier way to make a quick buck.
They pay for shipping; you simply print out a shipping label and bring your book or movie to the post office. In some areas, you can even leave the package in your mail box with some money, and the postman will take your package and leave your change!
Another quick way to make money on the internet is by reselling items on Ebay. See what's selling on Ebay, then check the prices at your local discount stores. Going-out-of-business sales are great places to find cheap stuff to resell on Ebay for a profit!
Perhaps the method of making money on the internet with the most potential for earnings is creating a successful blog, and equipping it with Google AdSense. Post all your interesting and original ideas, home videos, and political theories, get Google AdSense to accept your website, throw the html code on there and watch the money roll in! When you can make money in your sleep, you know you're doing somethin' right!
So always be on the lookout for what you have locally, whether your own creations or the best deals at your local stores, and throw them online for a quick buck!