We were checking some homes last night and I wanted to -of course- use the iPad for that. John L. Scott is a local real estate company which is one of the most innovative Microsoft shop on the planet. They not only use Microsoft's latest technology all the time, they actually make great use of it. I am not quite sure what they are using at the moment, but that's certainly a combination of ASP.Net and Silverlight.
So if you have an iPad, I would recommend you navigate to: http://www.johnlscott.com/, you'll be redirected to their mobile site. The UX is phenomenal, a lot better than browsing for homes on a laptop or a mobile phone.