There were several reports at the Google Web Search Help forums over the weekend reporting that the top Google navigation has gone missing. You know, that top bar, above the search box, that lists the other Google features you can use.
@rishil sent me a quick movie, showing how the bar went missing. Notice the top bar, keep your eye on how it disappears after he conducts a search:
The issue started some time on Friday night and continued into Saturday. I do not have the exact times, but I believe it was an issue for at least 12 hours. Google has not officially made a statement about the issue, but "top contributors" in the forum claimed Google was aware of the issue and working on a fix. It then showed up shortly after.