http://googleblog.blogspot.com/2010/05/search-more-securely-with-encrypted.html
I know there has been a lot of chatter about whether encrypting the entire Internet would make things slower.
In my experience, using a 2.9 GHz machine over medium-speed unencrypted wireless connection, SSL for Gmail and Search doesn't seem to be any slower at all. And I have the confidence that only the big boys can spy on me or introduce redirections ("302")