Use case: suppose you're browsing a website with your PC, then you go away to take a coffee. Your friend writes you a message "hey John! Please call me back as soon as possible!". The notification is shown for few seconds in the bottom part of the screen, then is hidden. You come back to the PC when the notification is already hidden and you can't see the message. The only way you have to see the message is moving the mouse in the bottom-right part of the screen or in the upper-left part. Your unread messages could wait for hours without the user can read them.

Solution: the user should be advised there are unread messages.

How: here you come designers :P I can suggest my simple idea, but of course you will have some better idea. Anyway... you already know the small visual effect you see when you move the mouse in the top-left part of the screen? I mean the small circles fading... well! You could display the same visual effect in the bottom-right part of the screen, until the user actually move the mouse in that direction.

In this way the user doesn't risk to have unread messages for hours. The small visual effect is not intrusive.

What do you think about?