Do Google Gadgets Work?

I was browsing through all of the Google Gadgets today and, while there are some really interesting ones, I have to wonder “do Google Gadgets work to help keep visitors on your website/blog?” Does embedding a game of Pac-Man make anyone stay on a website any longer if there is no interesting content?

What widgets/gadgets do people find useful to add to their websites that help to improve a users experience?