Out damn spot - cleaning your camera sensor

It is inevitable--if you use a D-SLR you will eventually see dark spots on your photos.   It is not caused by a defect in your CCD, rather a combination of the piston action of zoom lenses pulling in dust and the static charge of the CCD attracting that dust (in the same ways CRT's, remember CRT's, attracted dust).   Olympus pioneered self-cleaning CCD's but even self-cleaning CCD's eventually need cleaning. 

Most manufacturer's official line is that at most you should use a blower to blow the dust off the CCD.   That does help in a lot of cases.  Eventually, though you get welded dust--Thom Hogan's term for dust that is extra sticky dust.  At that point, manufacturer's recommend that you send the camera in.  This isn't really practical--at $40-$70/cleaning and if you don't live close to a center your camera will be AWOL for weeks.

There are a number of techniques that can help you clean the sensor yourself ranging from sensible to stupid.  Luckily, Fargo Enterprises has put up a decent FAQ on how to clean your sensor while minimizing (not eliminating) the chance of damage.   Be careful, replacing the sensor is very expensive.  Doing it wrong might mean you have to go upgrade to a new Nikon D700.

Fargo's Camera Cleaning FAQ is at http://www.cleaningdigitalcameras.com

Thom Hogan's article is at http://bythom.com/cleaning.htm