I don't know if this was ever reported on before, probably was, but I was watching a video for the band "Lead into Gold" (which happen's to be ex-ministry bassist Paul Barker's side project) because this band will be opening for ohGr on their upcoming tour, and I was curious as to what their music was like and to my surprise, Trent Reznor was featured in the video playing guitar. The best shots of him are 3:35-3:40. Oh, and would you look at that, just noticed the thumbnail to the video is him as well!

I then went to Wikipedia to read up on this band and this is what it had to say:

In the video for "Faster Than Light", Nine Inch Nails' vocalist Trent Reznor can be seen playing the guitar. He was rumored to have been in the area for the "Head Like a Hole" video shoot when he made his cameo.
Once again, I apologize if this is old news, but I found it fascinating!