Tasty Apps says of their gift managing widget Gift-It! that it "pushes Apple's Dashboard to the limit!" It's a neat idea: You create entries for all the folks you might need to buy gifts for (including yourself of course!). Gift-It! then installs a new button in the Safari toolbar (thanks to the somewhat controversial SIMBL). Now when you're browsing a site and see something that would be good to get for somebody on your list, you need only click the package button and you'll get a dialog box that allows you to select the recipient. That page's URL will then be automatically added to the appropriate gift list, which you can access back in the Dashboard widget. Here you can see how I've generously allotted myself a new camera from B&H. You can also enter birthdays into the widget for future reminders.
I have to admit that the widget is a little bit confusing to use (I can't quite figure out how to move something from the Wish List to the Gift Box), but the Safari integration is seriously clever. I think Tasty Apps is right to suggest that this is one of the more advanced widgets out there, and certainly has the potential to be useful (though I already do something similar to track gift ideas with del.icio.us tags, though without the Dashboard eye candy and birthday reminders of course).
Gift-It! is presently in beta and is a free download.