Well - I was hoping to hear that if I could not see it in Live View, it HAD to be on the viewfinder, but I figured that would not be the case.
But now I have more questions:
1) Dust between focus screen and viewfinder - on a K-x, I assume there is nothing that can be done, since focus screen is not removable?
2) When you say a "sensor cleaning brush", is that the same as a LensPen?
3) If it is on the mirror, my understanding is that Iv should just live with it, and not touch the mirror - correct?
Thanks again to everyone.