Avatars can communicate with each other by gesturing as well as by chatting. Many of the emotions that you might have used "emoticons" to show before can now be "acted out" by clicking the appropriate Gesture button.

The Gesture buttons are located just above the main view screen. Just click the appropriate gesture that you'd like everyone around you to see. There may be different gesture choices for each avatar.

Each gesture has a hot-key equivalent. One letter in each Gesture button is underlined. Just press ALT + the appropriate hot-key letter to send a gesture. That way you can send gestures to people while you're moving or chatting, without having to stop and use the mouse.