Sure. It's done all the time.
I wrote a blog on how to find lease-options and rent-to-owns. It's at http://www.trulia.com/blog/don_tepper/2010/03/how_you_can_fi
I'm not necessarily suggesting that for you--though you do raise the possibility yourself. But the situation is exactly the same. You're trying to find someone with a house for sale now, and you're trying to convince them to lease it instead. My blog will explain how to find those people.
To summarize (and read the blog; it's much more detailed), you want people who don't need all their money out right away. Often, the most receptive owners are those with vacant properties. They've moved; they're still making payments on the house but now there's no money coming in. Your pitch, basically, is: "Gee, it must be painful to have that empty house just sitting there, not selling, costing you money every month. I've got an idea that might help. Why don't we lease the home from you for a year. We'll take good care of the house, and you'll get your rent every month. In a year, the real estate market may have improved and you might have an easier time selling, and for more money."
If you like the house enough to consider buying it, your pitch is: "Gee, it must be painful to have that empty house just sitting there, not selling, costing you money every month. I've got an idea that might help. We'd like to rent your house for a year, and we'd even like the option of purchasing it. We'll take good care of your house, and you'll get your rent every month. And we're serious about buying, so we'd really like to have the option of purchasing it, too." Just be careful; Texas has some restrictive laws on how to structure lease-options. But it can be done. Or there's a technique using a land trust that'll accomplish the same goal.
Also, as Naima suggests, another group of sellers who'd be receptive are those with long days-on-market, whether or not the home is vacant. And look for properties that are listed both for sale and for rent.
Anyhow, read the blog.
Hope that helps.