I got my 5D less than a month ago, and I already have lint and dirt somewhere on the mirror of above the pentaprism where blowing air or simply rubbing it with soft (lens cleaner cloth) will not get rid of it.  I see these little dirt/hair fibers in the viewfinder only.  Images are clean, so the sensor is clean.  I did have a spot on the images too, but I followed the cleaning procedure of the sensor, Sensor Cleaning mode then blowing air on the sensor, and that fixed the problem. 

Does anyone know any tricks to clean it.  I hate spending another $50.00 to send it to Canon to get it cleaned.  Besides, it will happen again.

Thank You all

Hadi