Definite business opportunity there, the two services I have found (in this case I'm looking for Texas data) both consider using an iframe "integration".
Yes. I got hired to integrate MLS data and man was that a nightmare. Many are surprisingly low-tech and almost all use different formats. There is a half-assed attempt at standards (RETS), but that's for accessing the data not the data itself. Not to mention getting and presenting the data legally--each MLS group has different rules about what you're allowed to display (and it can be incredibly restricting). tl;dr the project went down in flames.
I'd love to see Google get ahold of the data and make it available through Base.
I'm sure Google will get there eventually, as they're doing with all industries that traditionally make information inaccessible. Google just enhanced Google Scholar to be a major competitor to Westlaw, which should make a lot of frugal lawyers happy.
