Contact--or have your Realtor contact--absentee owners. They own properties in the area, but are probably renting them out. The pitch, basically, is: "You may have thought of selling, but didn't know if the time was right or if there were any buyers. I am (or I have) a buyer for your property." Your Realtor can screen by type of property, number of bedrooms and baths, etc. That way, you'll have no competition, and possibly find a home even though nothing's currently on the market.
Hope that helps.