Discuss anything outside the other topic areas.
Google Books is a great new growing resource that really has to be commended especially for those older or rare books that are not readily available otherwise. And its free book range is increasing each week.
I came across this on http://www.new-science-theory.com who make some good use of Google Books.
It is a service from Google that searches the full text of books that Google scans,converts to text using optical character recognition and stores in its digital database itself and if we are talking about the benefits for authors or the publisher,out of print books need no longer be relegated to the used book market.
And anyone with an Android phone or tablet can get Apps from Google Play.
A good science news App is New Science Info.