If you have an Android phone/tablet or an iPhone/iPad/iPod, install the fantastic mobile app to help you access Google+ on the move. 

The latest update of the app lets you join hangouts (group video chat) and post photos in comments in the messenger (previously called the huddle). 

Check out this video for some ideas on what you can do with on the mobile app:

Check out an interactive demo of messenger (previous called the huddle) & instant upload, and download the mobile apps here. 

Here are a few screenshots from the updated version of the mobile app: 

If you don't have an Android or an iOS device you can access Google+ via your phone's mobile browser. Just go to http://www.google.com/+.