Google Talk is one of my favorite parts about Android. If you have other Googly friends, between Android, Gmail, and G+, they are almost always available. In Android 2.3.4, Google Talk got a big upgrade in the form of voice and video chat.
There will be many similarities to the to the Ice Cream Sandwich version of Gmail, which was the subject of Part 1 of this series. So go read about it or risk falling behind the rest of the class.