Is it possible to share/post to Google+ without using the +1 button?
e.g. Like a normal tweet button works with a url link: http://twitter.com/share?url=httpetcetcetc
Yes, you can.
https://plus.google.com/share?url=YOUR_URL_HERE
Edit: It works only with eff.org.
Edit: As of March 2012 it works on all sites.
Documentation for this sharing method is available on the Google Developers site.