Recently, a client of mine asked what the Gravatar option in Clip-Bucket was. I knew Clip-Bucket, and a lot of scripts, have it. Wanting to give a better understanding to my client of what it was, I searched the Internet for some more information, until I completely understood how it worked. Here is basically what I told him. This functionality is implemented in all the CB v2 versions.
Gravatar stands for Globally Recognized Avatar. It is an avatar, or picture, that is associated with your e-mail address. This means that whenever you signup with the e-mail address you set at gravatar.com, the same avatar uploaded to Gravatar will be shown.
First, you need to signup at Gravatar and upload the avatar that will be globally used.
Next, in your Gravatar supported website, ie. Clip-Bucket, you can enable the option in your admin_area (Stats and Configurations->Website Settings->User settings & registration) to allow Gravatar. To see its functionality, you just need to either enter your profile or comment.
There are more scripts that use Gravatar, for example the powerful CMS Joomla.
In my opinion, this a very nice tool, because you do not need to be uploading avatars on every forum, video site, etc.
Any questions or comments, do not hesitate to contact me!