Thanks to Wouter Gerritsma's blog "Wouter over het web" for this, which I have not seen mention of anywhere else. (The post is in Dutch and any misinterpretation is entirely my own!).
Google Scholar will now give a link to freely available versions of an item, with this link appearing next to the title of the item. It will still tell you how many versions of an item it has found, and if you click that information, give links to all those versions, whether free or not, but next to the title, in your main results list, there will be a link to any free version.
Wouter's blogpost has a screenshot showing an item with a link to the repository of the University of Utrecht. I tried this with the search calcium signalling bacteria, and this finds a copy of the paper by Norris et al in the Journal of Bacteriology in 1996 in Leicester Research Archive.
This, I think, is a very interesting development. There are of course search engines that search only open access material, and I have started slipping OAIster into some classes that I do, but this development to a search engine that we know a lot of people already use is very interesting. Will it push up traffic from Google Scholar to LRA - we shall see.