1. Sell Stuff Lying Around your House on eBay
You'd be surprised much money you could get from random junk laying around your house. Chances are if you paid money for it at one time, somebody else will buy it again for a reduced price. This can include clothing, electronics, lamps, furniture, and even small collectibles. You would be astonished at how much junk people will buy simply for nostalgic reasons. The point is however, raising for $500 using this method is a great way to build up capital.

2. Why Not Ask for Investments?
I'm not saying you have to get tens of thousands of dollars, but if you have a couple of friends and family members that can pitch in 50 bucks, then there is no reason why you couldn't do it. Just let them know that there's a good chance they will never see their money again, but if you do pull it off and make a good amount you can give them double their money back with no problem. Don't press too hard though as they are your relatives and you have to see them at Thanksgiving.

3. Apply for a Credit Card
You don't need a high limit or anything as $500 will do just fine. If you are extremely confident of the product or service you are going to sell, then this is the best way to get money fast. All businesses are in debt in one way or another and if you own money after a month that isn't necessarily a bad thing. I highly suggest though that once you do make enough money that you pay it off and use the profits from it to reinvest back in your business. It's never a good idea to be in debt for a very long time.

4. Soda Cans can Make you a Lot of Money
A man took his semi-truck and went to Canada and collected thousands of soda cans. After turning them in he made over $50,000. I'm just trying to throw some ideas out there for you as there are plenty of more ways you can make money to build up capital for your business.