Lou, When you switch to digital, one of the things you need to learn early on is how to clean a sensor. There are three cleaning levels you need to learn:
First is the blower: emphatically not a motorized or pressurized blower, but a more recent version of what we used to call an ear syringe. Every interchangeable lens digital I've had has a way to open the shutter and expose the sensor. A few puffs with a blower, being very careful to keep the nose of the syringe away from the sensor, usually will remove the usual random dust.
Second, if the blower doesn't do the job you try a brush. The Arctic Butterfly is a good choice. Ideally you don't actually contact the surface of the sensor with the brush. Instead you charge the brush with static electricity by twirling it or by some other means and then get the bristles close enough to the sensor that the dust jumps from sensor to brush. In practice you usually contact the sensor's filter since there's no way to do this as precisely as you'd like. This procedure can be quite effective.
Finally, if neither blower nor brush does the job you first use the blower to get rid of hard dust -- the kind that can scratch the filter over the sensor -- and then do a wet cleaning. Instead of going into the details about that I'll give you a reference that goes into detail about all these approaches:
http://www.cleaningdigitalcameras.com/methods.html.
If you check your sensor regularly and clean when you need to it shouldn't be necessary to take the body to a shop to get the job done. Furthermore, if you're off in the boonies when the sensor needs to be cleaned you're out of luck if you don't know how to do it yourself.
