The divider page sounds like a great idea, and it ought to be completely separable from the scanner choice. I could see people wanting to extend the 'divider page' concept into 'label stickers' that can be put directly on many pages. Barcodes may have all the desired properties already (easy to print, easy to find in a scan, easy to read, etc).

I've been thinking about my own paper scanning problem, and I was leaning towards building a copy stand that would let me use a digital camera as the scanner. That would be roughly no-cost, and it would gracefully handle odd/delicate pages such as newspapers. Leasing time on a higher-end scanner would probably be better for me, though.