Okay, I want to develop some apps for Windows Phone 7 (just by my self as a hobby) and I live in Denmark.
Microsoft tells me that I should send them a W-8 form before they can pay me, that it should most likely be a W-8BEN form, and that I should get an Individual Taxpayer Identification Number, in order to take advantage of the tax treaty between the US and Denmark.
Now, on the W-8BEN form, it says that I should not use this form if I am "A person claiming that income is effectively connected with the conduct of a trade or business in the United States". But isn't that exactly what I am, and shouldn't I be using some other form then?
And when I want to get an ITIN, I must "Use the latest revision of Form W-7, Application for IRS Individual Taxpayer Identification Number to apply. Attach a valid federal income tax return, unless you qualify for an exception, and include your original, notarized, or certified proof of identity and foreign status documents.".
Since I am tax excempt in the US, as per the tax treaty between Denmark and the US, should I just include my "original, notarized, or certified proof of identity and foreign status documents."? And what exactly could that be, a copy of my passport?
Any help is greatly appreciated. 
