After a very long development time of more than 2 years CakePHP 1.2 has been released today/yesterday (see the announcement).
Since RC4 a small new feature has been added: it is now possible to specify whether the validation of an URL should be strict (“strict” meaning the protocol must be provided, i.e. “http://example.com” is valid whereas “example.com” is invalid). If you want to use the strict URL validation, you have to use in your model something like:
public $validate = array('website' => array('rule' => array('url', true)));
For people currently using Cake 1.1 and considering to upgrade to 1.2 I recommend to have a look at Migrating from CakePHP 1.1 to 1.2. And to budget enough time for the migration itself because so many things changed…