Try searching for, say, 'github', and you will find that github's URL is displayed as: "www.https://github.com/" - it happens for any site with https in the URL.

It only works sometimes, though - it happens to me when if I search while logged in, but not while logged out. For evidence see this screenshot: http://dl.dropbox.com/u/2986043/Screen%20shot%202011-03-30%20at%2018.25.41.png

I know this isn't an interesting observation per se, but it's rare you see Google making a blatant misstep.

(Also it seems to me that telling HN about this will probably be more effective than submitting a bug report.)