I really like www.domain.com.au new refine search function. It is completely reactive to the data on the screen.

Their old method was selecting how many bedroom or more, now you can checkbox exactly how many you want. Which is cool but besides that it will only show you options that are relevant to the current data. In other words, if there are no 1 bedders, then 1 bedroom is not an option.

Easier to use, and most importantly, it is neat and works sharp. No useless graphical crap, nice and quick.

http://www.google.com.au/base/

Google Base, seems pretty cool, what they are doing is pretty much just putting more search options when buying. Companies with an online shop can plug into Base via an API or an XML upload to publish their inventory.

It is a good concept and hopefully the implementation of the searching will be tight enough to be user friendly. Having said that, it is Google so it should be pretty sweet.