If your blog is created by Blogger, you may have wished there was a way to easily browse through the images you have uploaded for your posts. Or perhaps you wished for an easy way to display the images elsewhere.
You may not have realized that if you use Blogger (whether using blogspot, or a custom domain) all the images you have uploaded are available for your private viewing via Google's Picasa. If you have multiple blogs, each blog will have a separate album folder. And these folders will also be separate from any additional albums you create through Picasa's interface.
You sign into Picasa in the same way you sign into Blogger, as both are connected to your Google account.
In Picasa you can make the album public, if you wish, add captions, email the images to friends or relatives, or even order prints. (Though the prints aren't likely to be of great quality unless you've uploaded the images at a high enough resolution.)
When viewing an individual photo they provide on the right hand side the html code for linking to or embedding the image elsewhere.
If you delete images from your blog's Picasa album, they will disappear from your blog (and vice versa.) By default they aren't viewable by anyone who isn't signed into your Google account, so if you have no interest in using the Picasa website, you don't have to worry about anyone else viewing the images in this fashion.