Dust has been a problem for digital SLR cameras since they were first introduced. If a tiny speck of dust gets inside your camera and settles on the glass in front of the camera's image sensor (CMOS or CCD), it will show up in your photos as a spot that repeats in the same place. Trying to remove contaminants from the sensor is something that should be done with extreme care.
We have checked with the major camera manufacturers and they all caution that the glass in front of the sensor should never be touched by anyone except a trained technician. If you were to scratch or damage the glass, it would result in a very expensive repair. Their unanimous recommendation is to use a blower (NOT CANNED AIR) in conjunction with the camera's cleaning mode (menu option used to access the image sensor).