You can use Picasa Web Albums to create a Flash slideshow to embed in your site. Each slideshow features built-in playback controls, size options, and the ability to display captions. You will need to have a Google account to sign-up for Picasa.
To create and embed a slideshow with Picasa, follow the steps provided here: Embedding albums, images, and slideshows.
Once you have the code necessary to embed the slideshow onto your site, you can add this to an HTML Code Widget.
- In your Sitebuilder, go to Widgets > Popular.
- Drag and drop the HTML Code Widget.
- Paste in the code from Picasa.
- Click "Save".