Msmith is correct - most scanners can scan multiple photos at the same time, especially if you use VueScan. On my Epson V600, I can scan 4 photos to separate files in 15 seconds at 400 dpi using VueScan. I've written an Instructable to show the details of the process.
msmith44 wrote:
An Epson VT 600 will scan multiple photos at the same time as single images. The length of time for a scan is, in part, a function of the image quality setting. BTW, other printers will do the same thing not just a VT600.