Those dusty old photographic slides might not be lost, even ones that have faded to red. The Nikon CoolScan V dedicated slide scanner (~C$550 in 2008), in conjunction with VueScan, after-market scanner driver package (US $40), can resurrect damaged slides.
The image below is a small section of a 50-yr-old Ektachrome slide. On the left is the image with no processing, just as the transparency appears when viewed by eye, with a strong red colour cast from age, and dust specks. On the right is the same image after being scanned and then processed by VueScan.
The colour correction is dramatic but not all that hard for the software to do; the slide's colour dyes have faded at differing rates (red being most durable) and the correction software shifts them back into proportion.
Accomplishing the dust removal is more involved. The scanner has a fourth scanning channel in the infra-red range. Infra-red light can pass through most films but not through obstructions (eg., dust) on the film. That infra-red channel information tells the software what areas of the picture need to be patched by filling from surrounding pixels.
Dust patching is a major help. With scans from an old flatbed scanner that did not have an infra-red channel, I sometimes spent hours per slide fixing up the dust specks, prior to getting this Nikon slide scanner about a year ago. Now often I don't even bother trying to blow off the dust with compressed air, etc.
Unfortunately, even with these technologies, slide scanning is still tedious. Each slide takes about a minute; inconveniently long to wait, too short to do much else. It can be done somewhat in the background, but it's still disruptive. I did a lot of reading of news and writing of email while scanning.
Ektachrome seems most vulnerable to colour-shift fading. Some Kodachrome are also terrible, but others are great (some of my father's Kodachrome from the 1940's are just about gone, others are like new). I wonder if the variation is due to processing issues, the film, storage, or the exposure? Or maybe it is due to projection; I've heard that a slide loses 50% of its colour after 4 minutes of projection, due to the intense light.
Once digitized, a photo won't fade or get dirty. But scanning is time-consuming work.