What is offering a real return of 20% these days?
In many places the prices being asked for purchasing real estate including everything results in payments higher than what you can rent the property out for- even if you allow for depreciation. Remember to include maintainance costs and the probability of a certain amount of time for the property being vacant between tenants meaning no revenue coming in on it.
I'm 35, 3 kids, no I'm not living in this house until I die, and I'm pretty attached to the cash I makeDo you plan on living in the house till you die? Do you have kids or plan to have kids? They are expensive. What is your risk tolerance? I will take the money off your hands, then you wouldn't have to worry about it.

I guess I'm the contrarian here.
Sell your house. Pull out as much equity as you can now, before house prices collapse by another 30 to 50%. Invest the proceeds, along with your current income and rent a place until the housing market recovers.
Here's a short article with some example numbers: http://www.12retire.com/?p=26
I had a friend who told me a few years ago that housing prices would collapse that I should sell my place, invest the money while renting, and wait for the prices to fall and then buy back or get another house. Well even after prices have dropped some, they are still more than twice what I paid (around the year 2000- I was lucky enough to get in just as the boom was starting) and if I repurchased today I would have to pay a lot more to get the same place and face higher property taxes because of it. Those higher property taxes would be with me as long as I was an owner of a home. There is no certainty that you could come out ahead and would probably lose. Your plan involves a lot of risk. I prefered not to take that risk with my home. For me, the idea is to have it paid for by the time I retire so I do not face that expense when my income is reduced.
The wife and I have gotten our bills and expenses down to the point where we have $2k/month saved (all bills paid, food, etc etc).
What would better financially: paying down the mortgage faster to where it is gone in 10 years (saving us hundreds of thousands of dollars) or investing that money and have it work for us for a change?