Adding a Google+ Widget in Your Blog
One important thing about widgets is that it needs to be attractive enough for the user to interact with. The link below is one way to add a nice customizable badge for your goolge plus account. It doesn't just create a one-click button for your site or blog it also allows you to see the number of people who have you in their circle. You can also add an update list for this similar to a twitter widget.
To create the said widget, go to widgetplus and customize your own widget. Make sure to know first your google plus ID by visiting your Google+ profile. The G+ Id can be seen on the address bar when you go to your profile, the number between the https://plus.google.com/u/0/ and /posts is your google plus id.
You can view the live demo of the widget on this blog (See upper corner of my sidebar). Go and try it!