I’m stuck with a dilema…
Scan everything at full res thus preserving the maximum ‘quality’ of the image.
Scan everything at a screen-fit res and save an awful lot of time and space.
What would you do, or what have you done?
edit: I’m talking about old family photos. I have thousands of them.
Scan them at high res. That way, if you ever want to print them you have them.
It’s easier to do hi-res and then make low-res copies than it is to do all low-res and scan them again when you want hi-res.
Once you have them all in, then you can run a batch job in Photoshop to make smaller copies.
I’ll scan them high res…
Or get someone else to do it 
I’ve scanned old 35mm photos, and the scanner software indicated the originals were somewhere between 300 and 400 ppi, depending on the lighting. I don’t know if increasing the resolution would provide a quality that may not have been there in the first place.
I can’t argue with the time consideration, but space is not an issue. Five years from now the space taken by those high resolution scans will seem insignificant. Think back to how much disk space you had available 5 years ago and how much you have now.
I admit, Space was just thrown in there to add weight to the argument against scanning at high res.
What I might do is take the scanner and photos (and a portable HD) to work, where I have plenty of spare time to do this.