carhartl/jquery-cookie — pull request #60 by bmaland (2012-04-19 19:56:55+00:00)
Title: Added support for `domain: 'all'` which sets the cookie on the top most domain possible

This functionality is present in various server-side frameworks (e.g. Rails) and can be quite useful - especially if your site run on multiple TLDs which in turn has several subdomains.