Google has begun experimenting with securing its search site using TLS/SSL. This is the https scheme used by many ecommerce sites to encrypt web traffic between browsers and servers and keep the data safe from eavesdroppers.
Not only is the data encrypted, but clicking on any results will not send the referrer information to the target sites unless they are secure pages as well. This is welcome news to privacy proponents, but not so to sites that collect statistics on their visitors or have their sites' logic wired to the referrer data. Of course if you are wary of Google itself collecting information about your habits, this initiative won't help a bit.
Secure pages have the disadvantage of being more CPU and memory hungry over their regular counterparts on both clients and servers. But I guess Google has decided that with hardware getting cheaper and more powerful these days, this is not a significant barrier anymore.