Now you can optimize your major images through site .Google now support images in site map .

Image tag is

<image:image>

<image:loc>

</image:loc>

</image:image>

 

Read the full article at: http://googlewebmastercentral.blogspot.com/2010/04/adding-images-to-your-sitemaps.html

I think it is good for webmasters who own rich images sites or blogs. Now, they can easily optimize their important images via Google image search.

are there any tools to generate Image Sitemaps sitemaps, Im just looking in to Google webmaster guide and it say that it is good to have one.

Thank you for contribution.

Great information! It will definitely help the website having large image database.