The new default mode got some performance and usability issue.
http://www.pcmag.com/article2/0,2817,2372489,00.asp
http://lifehacker.com/5633004/how-to-turn-off-google-instant-search
Click "Instant is on" in the result page to turn it off (no easy way to turn off the even newer instant preview though http://www.ghacks.net/2010/11/11/how-to-disable-google-instant-previews/ http://lifehacker.com/5688543/hide-google-instant-preview-with-an-adblock-filter )