Sabrina Huang, a San Jose, CA Realtor that I met at the PFRE Seattle Workshop last April pointed out that I shouldn't excluding point-and-shoot from my review of real estate cameras. She's right, today's point-and-shoot cameras are pretty amazing. I haven't mentioned them because the majority of readers of this blog are professional photographers and DSLRs are more appropriate.
The primary selection criteria for point-and-shoot cameras to use for real estate has to be the ability to shoot wide-angle. Sabrina teaches photography classes for other Realtors in the San Jose area and has put together a list of point-and-shoot cameras that will work well for real estate photography.
I have the first camera on Sabrina's list, the Canon G9, although I don't have the wide-angle converter for it. The G9 is the most amazing camera I've ever owned! It never leaves my side. This is the camera I use on my PAP pole. What blew me a way when I first started using the G9 is that it's RAW files were slightly larger than RAW files from my 1Ds. There is certainly no quality problem with the images from these pocket sized cameras. The only real downside with using them for real estate is that you have to live with a fixed focal length in the area just above or below 24mm (35mm effective focal length). This is in now way a show stopper, it just reduces flexibility.
Update 7/27: A reader pointed out that Sabrina's post indicates that the a wide-angle converter will get the Canon G9 to 24mm. To do that you need to use the Raynox HD-6600PRO58 58mm wide-angle adapter. The Canon WCDC58N does not go that wide, it only has a focal length multiplier of .75 where as the Raynox has a multiplier of .66 which makes the G9's 35mm lens get to 23.1mm.