You decide whether you want friends to know if you're not using your computer. Here's how to reveal or conceal your Idle status:

1. Click the Messenger menu in Yahoo! Messenger.
2. Select Privacy Options.
3. Locate the "Idle Status" section.
4. Choose whether you want to be shown as "Idle" after a period of time, or never be shown as "Idle."
5. Click OK.