Ask HN: Which are the most awesome "Instant Search" sites you have seen?

Instant Search is popping all over the place and is taking the whole web to a whole new level of convenience and aesthetics. http://www.shelfluv.com/ is an elegant example. Can you submit all the Instant search apps you have seen so far so that the HN community can vote the best up.

Bing has taken Instant search to a whole new level. Which other sites do you think can benefit from such Instantness?

What are the general techniques that make kick ass Instant effects... Eg: 1)The dynamic shelf in shelfluv, 2)The seamless transition from search page to search results in bing. 3)Faceted filtering in Bing, Hipmunk, http://milo.com/ etc.

Are you working on an Instant Something right now?