A neat website that allows you to make jigsaw puzzle widgets out of uploaded images. Even if you don't upload anything, you can choose from hundreds of existing jigsaw puzzles and easily get the code for the widget. Lots of anime/manga images. Click on one you like, and look for [貼り付けコード] near the bottom of the explanation. You'll see the code there.

Reversi using black and white rabbits. The widget is nicely designed and unobtrusive. Get the code right from Bloglue.