I sometimes find myself wanting to make large changes to my Address Book and iCal entries -- the kinds of things that I don't seem to be able to do within the applications themselves. Things like being able to search for a group of iCal events, select them, and then change them all to a new iCal calendar. Using Bento, I can do just that. It is a great way of cleaning up the Address Book, too.
You just open Bento (I'm using version 4 now, but 3 could also do it), navigate to either the Address or iCal source lists, choose the list view, and start editing. Could not be easier.
[crarko adds: I tested this, and it works as described. Bento obviously is not free, but there seem to be a lot of people out there who using it.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110421062106545