The Samsung Galaxy S includes the custom widget “Buddies Now”. This widget implements a carousel that can be rotated with a a press-drag. Here’s a description of the widget:
http://www.phonescoop.com/articles/article.php?a=389&p=2830&g=3054&h=25816
This widget exhibits features not commonly seen in other widgets: animated images and interactivity beyond a simple click. Does this widget take advantage of Samsung’s custom launcher (TwLauncher), or is it a standard widget? If it is a standard widget, what API does it use for the animation and interactivity?
It’s using Samsung’s custom launcher to provide those features.
To see what can/can’t be done with app widgets currently look here: http://developer.android.com/guide/topics/appwidgets/index.html
Specifically this section:
So you don’t have the UI components at your disposal when creating app widgets to design something with that level of interactivity. Not if you are targeting the stock launcher anyway.
However, from what I’ve seen of the Android 3.0 SDK, I think this level of interactivity will be possible on the stock Android 3.0 (Honeycomb) launcher.