Even though there is no "log out" feature, there are many glitches in the game that will allow you to log out and avoid closing the entire game and restarting it. Once such way for log out (or disconnect) is to jump as far as you can back and forth. Once in the air during a jump, immediately move the pointer back to where your character jumped from and click while you are still in the air. Keep doing that back and forth movement and you will eventually disconnect and be sent back to the log in screen.
Another glitch has the same outcome but is done differently. First, go the "actions" and hotkey at least four of them (for example, F5 for Wave, F6 for Lie, F7 for Cool, and F8 for Sit). Start pressing all four of these hotkeys at the same time. Your character looks as if he or she is having a seizure, and you will get disconnected.
These glitches are useful if you want to log out and relog in with another character.