Comment 8 for bug 248475

To make oneself invisible on a google talk account, paste the following into the XMPP Console (Tools > Plugins >XMPP Consol (normally at the bottom) enable it:

<presence>
<priority>5</priority>
</presence>

<presence type="unavailable">
<priority>5</priority>
</presence>

<iq type='get'><query xmlns='google:mail:notify'/></iq>

Repeat the above step whenever you want to refresh the buddy list..
# The last line of the code causes the server to return Email Notifications. #