If you are short on budget but high on creativity there are quite a few ways of earning online. The most commonest way of earning is Publishing Business. Start a blog sign on Adsense and if you can generate pageviews you are in for some good money.
Or own a Handycam, shoot some cool videos ( Even Mobile will do ) and upload in sites like YouTube and Revver which do pay for content.
If you are high on entrepreneur drive and have the moolah and risk taking apetite then think big. Start with a Idea and nurture and grow it and sell when you have ample of customers. Reaping millions of real dollars.
There is money to be made on thw web, and you are free to harness the web.