Sergey Alakov, who finds all this crazy Google UI tests, reported to me on Twitter that Google is now testing a "back to top" button that floats over the search results when you access it on your smartphone.
He said the "experience isn't great" adding that it is "not very responsive."
Here is his screen shot:
He was using Chrome on iOS but I cannot replicate this when I tried it.
Forum discussion at Twitter.
