Real Estate: I don't have anything to back this up, but lots of real estate markets have been blowing up. My neighborhood is up about 20% year on year, but we've seen a lot of rentals cropping up. My guess is that either REITs or well-heeled investors are buying loads of houses at the low end and renting them out. Rent ~= mortgage payment, so you're just out the maintenance and handling, if that, and you're gaining equity.
If you go onesie - twosie, and one goes vacant for a few months, that nukes a lot of your (not tremendous in the first place) profit. At 20-25 houses (@200k/house, that's about $4-5M total capital investment), your risk probably isn't too bad.