Its easy as this:
If you know further Blogs or News sites, using BIGACE and the Comments plugin, edit this page and post your link!
There are people outside who afraid of the personal profile data, which could be collected by the Gravatar running company/people. You should Google for more information and read one or two articles before you activate your account!
The biggest problems:
The consequence could be, be to create a free email account and register this one as Gravatar. Post with this email account and be happy :)