I quite recently upgraded from 10.04 to 12.04 so I'm still adjusting to the switch from gnome to unity.
One new thing is the way I get notifications from gmail and pidgin. I've got it working so that they are both available via the little e-mail icon by the clock.
However, they don't automatically activate upon login. In order to get notifications from gmail I have to manually klick it once to start the underlying application.
!
After I've clicked it I get another row with the inbox status.

The same is more or less true for pidgin, it got no extra status line, but the application starts the first time I click it rather than autmatically when I login.
So the question finally is how I get these to auto-start?
I guess I could add pidgin to 'Startup Applications', but then it'll pop-up every time I log in, I'd like it to start minimized.
