Following on from my previous post, you may be wondering how you can actually find hangouts to join. If you've been invited by a friend or colleague, or you're in a particular circle, you should get to see a notification that a hangout has been started. However, if you're not actually in G+ at the time (you mean that you're not in there all the time??) that's not very helpful. Even if you are keen, you might simply want to join a public hangout to see what's occuring. There are a few ways in which you can do this. The first is to visit a site called GPHangouts, as this will provide you with not only a list of hangouts that are taking place right now, but with hangouts that are scheduled for some time in the future. You can also use this site to publicise your own hangouts, if they are public.
Another option is to use a plug in for the Chrome browser. There are a few of these available, such as My Hangouts, or Hangout Canopy for example. There's also an app for the iPhone (and possibly other smartphones as well), which can be used on the iPad as well - Google has a good listing that you might want to have a look at. I found a really nice blog posting that shows this in some detail. Of course, if you're using an iPad or an iPhone, instead of having the camera facing you, you could always do it the other way around, and guide people around a physical resource, like a library for example.