Go to your Gmail Settings page, switch to the Chat tab, choose “Chat Off” and click the “Save Changes” button. Alternatively, you may use this link to directly access your Gmail Chat settings page. You can re-enable chat in your Gmail by using the “Chat On” option.
I think most of us use gtalk application for chatting. Isn’t it? Then why do we want chat option in gmail? It’s quite boring and takes major part of the time to load the page. By doing a simple tip we can completely get rid of the chat box in gmail and save lots of time to load the page.
This setting to disable chat may have been available in regular Gmail accounts for some time but it was only recently added to Gmail for Google Apps accounts.