How do I continue investing after I've spent all my money on my first 2 properties?

[Michael V]

After purchasing 2 rental houses in two years I've learned more than I could have ever imagined. This is clearly the way to create wealth and I am in love with it. I now find myself in a position where I have spent all my "investing money" on the first 2 properties and still have the desire to purchase more. I don't want to wait for the properties to produce enough cash for another down payment. I want to buy sooner, and I have the feeling I will keep wanting to buy at a faster rate as I get better at this. That's why I need to figure out another way to invest without having all the cash up front. I have a handful of contacts that would invest with me, I'm just not sure how to set up the terms and structure this type of deal. What are some ways that people have gone about this and have been successful?