For those who haven’t heard about it, Google+ allows you to group networks and contacts in visual circles (and share information similarly to Facebook). Google + is kind of just added functionality to your Google account and if you are already have a Google account, more than likely it will be rolled out to you eventually (following the pattern of implementation for Buzz and Wave).
There is a safari extension for G+
http://google-plus-network.blogspot.com/2011/07/safari-extension-for-google.html so it seem that it does; although I didn’t see anything specifically in G+ help about safari.