I love the current escalation in the battle of the search engines. Since Google came out of nowhere a few years ago and ate all the other search engines for lunch, the response from that camp has been less than impressive. With their recent efforts, Yahoo! and Ask Jeeves have finally figured out what it is that makes Google so successful (and Microsoft wants to take a stab at it too).
It's the user experience, stupid.
Advances on the internet and the web are typically heralded as technology-driven. Robert Morris from IBM argued last year at Etech 2002 that -- and I'm paraphrasing from memory here -- most significant advances in software are actually advances in user experience, not in technology. Mosaic was not an advancement in technology over TBL's original browser. Blogger is a highly-specialized FTP client. IM is IRC++ (or IRC for Dummies, depending on your POV). The advantages that these applications offered people were user experience-oriented, not technology-oriented.
Google's success in the search space due to their focus on user experience has lent significant credibility to this way of thinking, so much so that their competitors are now scrambling to catch up on those terms. As someone who deals with user experience professionally, it's great to see this happening.