If you use Growl on the mac I am sure you have had lots of notifications on your screen at any one time. Just now I have been syncing many files on dropbox. There are several thousand html files for many different books.
I was unaware of exactly how many files there were, I was downstairs for a brief while and when I came to my mac I was faced with...
Luckily there is an easy way to close all of the windows, you don't need to close each one individually. If you hold the option key, then click on the X on one of the notifications it will shut them all for you.
I am always interested in feedback so feel free to add any comments, or you can mail me here, also if you would like to submit a quick tip with full credit and links back to your site then also feel free to contact me.