Widget Wars
Yahoo! renamed Konfabulator Yahoo! Widgets, and it has greatly expanded the widget gallery (it seems). I love these widgets. They're fun. Strategic value: They give the company a presence on the desktop, beyond the browser — blah, blah, blah.
Now, Google has offered an API for its personalized homepage — essentially a widget-making tool. This doesn't put "modules€ (as Google calls them) on your desktop (that's for Sidebar). Rather it puts them on your Google personalized homepage.
There are plenty of these that have a local dimension (maps, weather, transit schedules, etc.).