First of all, this 'guide' isn't WoW specific, I just thought I should post the address of what I thought was a useful website.
GuerrillaMail - Disposable Temporary E-Mail Address
Basically it is a website that allows you to create a random email address and use it for 15 minutes (If you need more time, you can add another 15 minutes until you are ready for it to go). You can also reply to emails that are sent to you, so I suppose it could be useful for signing up to websites that you don't trust.
Not sure how this could be used for any particular scams, but use your imagination.
Enjoy.