Anyone wanting to use it needs to go to https://www.google.com (note the https:), and it appears it only applies to web searching - not images or the other searches. Read more at:
- Official announcement on Google's blog
- CNET article
- Google's "About SSL Search" page
- Wikipedia article on SSL and how it works
This is good for those library patrons who want extra privacy while searching the internet. However, online privacy increasingly seems to be an illusion (remember, Google will still see and track these searches - this just cuts down on other people monitoring the searches).