When I cite from Google Books I use something like this: <ref name="Wilson">{{cite book|last=Wilson|first=Carol|title=Freedom at risk: the kidnapping of free Blacks in America, 1780–1865|publisher=University Press of Kentucky|date=1994|pages=43–44|isbn=0813118581|url= http://books.google.com/books?id=ptFqye_hg54C&pg=PA43%7Caccessdate=2009-... }</ref>
That makes both a direct link to GBooks with the first cited page open, and an ISBN link for general book sources.
The refTools gadget makes it easy to copy-paste the details from the GBooks information page. A tool that automatically pulls the fields from Google and outputs the template would save time.
I live in Sweden and I never had a problem accessing GBooks. Is it only blocked in some countries, or are some parts restricted?