"Every image you shoot on a film SLR is made on a fresh frame of film. Even if somehow you do get dust on one, the next one is likely OK, and after 36 exposures you get to start over again with a new clean roll. This "paper towel dispenser" approach just doesn't carry over to digital though. Every image you ever shoot on a digital SLR will be made using the same CCD or CMOS sensor, and sooner or later you will have to deal with dust spots on that sensor."
Nice resource for the brave-hearted. Beware the Scotch tape approach though!
Sensor Cleaning: Where Is That Dust Hiding, and What Do I Do About It?
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