Here's the company that 'discovered' the exploit and has a test so you can see.
http://secunia.com/multiple_browsers_idn_spoofing_test/
http://www.payp********l.com/ (this is the link that they have constructed)
Not that I like Secunia much, I don't think they are an honest white-hat company, but, they are the only one that had a valid test that I could see.