[ugh]

And it doesn’t break the back button! I was a bit worried about that but you can either make a ‘snapshot’ of the current search results by pressing enter or clicking the search button (just like before only without page reload) or by just waiting a short time (about three seconds), presumably so as to not clutter up your browser’s history.

It’s a really smooth experience and they seem to have though of everything.

[zach]

Managing browser history was the #1, #2, and #3 issue I had to deal with when I was doing a similar project. If you are very careful and clever (I recommend the jQuery history plugin) you can make it work properly, but it's a headache.

Google has made it very slick, although they at least have a fallback: "oops, Google Instant won't work on this browser (cough, IE) so here's Google Brewed." If you bill your service as instant search, you need to work with even lame browsers.