Specifically open houses? I check the Sunday newspaper (The Washington Post) and Craigslist). I'm a Realtor, so I also check the MRIS, but the Post and Craigslist give me all I need for what I'm looking for. I drive neighborhoods all the time to get the feel for them, to look for properties whose owners may be distressed, to talk to neighbors who know what's going on. Getting out there "on the ground" is absolutely necessary. And sometimes on Sunday I'll drive certain neighborhoods just to make sure I didn't miss anything in the Post or on Craigslist.