Gtalk, Google’s messenger application, gives you desktop alerts whenever one of your contacts signs in, you can opt in or out of these alerts. Similarly, if you sign in to chat via Gmail in Chrome, you can opt to get Chrome alerts for whenever some one IMs you. What you can’t do is get an alert when someone signs in. This is a slight drawback that means if you’re waiting for someone to come online, you will need to keep revisiting your Gmail tab to check their online status. GTalk Contact Notifications is a Chrome extension that gives you Chrome alerts whenever one of your contacts signs in and is available for chat.
You must be signed in to Gmail for the extension to work. The extension works for both Google App and Gmail accounts. You should have Gmail open in at least one tab in your browser, the tab doesn’t necessarily have to be active and you can minimize all Chrome windows. Whenever someone signs in to Gtalk, you receive a desktop alert from Chrome.
The notifications by default disappear after 3 seconds, however, you can modify the time for them to disappear or you can set it so that notification remains active until you choose to dismiss it yourself. To edit how long the notification remains on your desktop, go to the extension’s option and define, in seconds, how long it should appear. Reduce the time interval to zero if you want it to remain on your desktop until dismissed. click Save Info to save your changes.
The extension is useful if you sign in to different accounts on GTalk and Gmail and would like to be notified when one of your Gmail contacts signs in. It is also useful if, for some reason, you don’t have Gtalk installed on your system or you’re on a netbook (think Chrome book) and you would like to be notified of online contacts.