1. A method for communicating between a website and an untrusted website to create a web mashup on the website, comprising: setting a domain property of the website and a domain property of the untrusted website to a same document domain to allow direct communication between the untrusted website and the website; creating a mediator frame that points to a page on the website; creating an untrusted frame that points to a throwaway sub-domain; and passing data between the website using the mediator frame and the untrusted website using the untrusted frame to create the web mashup on the website.
11. The method of claim 1 , further comprising: determining which type of domain code authorization a browser on the website uses; and exchanging data between the website and the untrusted website based on the type of domain code authorization of the browser.