In my recent review of Growl, a third-party notification manager for OS X, I didn't really have the space to discuss usage of the program in very much detail. While usage is generally straightforward--just install the program, configure your notifications, and let it go to work--there is one little timesaving trick you may appreciate if you've got a lot of Growl notifications enabled.
In my case, I have Growl display a notification for each new iChat message I receive (using the Growl integration available via Chax). For those times when I step away from my machine, I've set my Growl iChat notifications to remain onscreen if they're not actively dismissed. This works great in general, except for those times when I leave iChat running and then leave the machine for a few hours. When I return, I find my screen littered with Growl notifications for all the messages I've missed...whoops.
You can get rid of each notification by clicking its individual close box, of course, but with sometimes 50 or so sitting on my screen, that's a very tedious task. As it turns out, there's a simple way to close all notifications at once--just hold the Option key before clicking on the first notification. Note that this trick will close all notifications, not just all notifications from one program.
So if you ever find yourself buried in Growl notifications, just remember the Option-click trick--it's a fast route to a clear screen.
This story, "Clear All Growl Notifications at Once" was originally published by Macworld.