Martin Zwilling posted a summary of the Top 10 Funding Sources for startup companies.
I personally funded my current company with the proceeds of the sale of a previous business and lots and lots of sweat equity.
While Mr. Zwilling mentions bartering services for equity, it is also quite possible to barter services for a profit sharing arrangement with the people who help with a particular project. This way the company equity remains with the founders and yet those who take the risk to invest in one or more projects can be rewarded for their time investment once that project takes off in the marketplace. It is also vital to never underestimate the importance of choosing the right co-founders and early-stage advisers! A good financial advisor, for instance, may just agree to provide free advice on business structure and tax consequences with the understanding that you will first come to his firm once a payroll is established.
Overall, this is good stuff folks. Check it out!