If doing it yourself, I would urge caution before buying a film scanner. These can give great results, but they can take a while to scan each slide (or neg - they can do those as well).

I used to sell scanners, and it was the classic enquiry "I've got X thousand slides/photos" blah blah blah. If you max out the resolution, then you could be looking at a minute per slide depending on the speed of your PC. That's before you've got into cropping, improving the pic etc.

Even with a fairly sensible resolution, the process can be rather slow.

If you have a good digital camera and an adapter is available, I would consider that. Else as an earlier poster said, project on to a screen. Then photograph that (put the camera onto a tripod as close as possible to the projector). If your camera has a remote control, its so simple. Projector remote in one hand, camera remote in the other and away you go - as fast as your camera can go until you run out of memory. Then upload and continue. I got best results by setting my camera to manual and experimenting a bit first.

My projector was a rather poor one. Although not immediately noticeable on the screen, it was clear afterwards that the pics were brighter in the centre than in the corners. Since this was a systematic error, I was able to create a filter in Photoshop and apply to each in turn.