Next week we will start offering an encrypted version of Google Search.
Right now, if you go to https://www.google.com/ you are redirected to the non https version, http. Even if you try appending a, https://www.google.com/search?q=google, to a query you, are redirected back to the main non-secure Google search.
This may change according to Google's own words. Exactly how Google will release "an encrypted version of Google Search" is not clear. But it should launch this week, according to that post.
Forum discussion at WebmasterWorld.