Scan it in two passes and stitch back together in an image editing program. Two points: you need to make sure both scans are at the same angle (get creative with a ruler or other straight edge and some masking tape ) and you need to disable any auto-exposure settings in the scanner software so you get the same exposure for both halves. This image in the gallery (http://www.apug.org/gallery/showphot...00&ppuser=2807) was scanned in two goes and this (http://www.apug.org/gallery/showphot...00&ppuser=2807) one shows what you get if you forget to disable the scanner's auto-exposure (look at the bottom border) - whoops!...

Cheers, Bob.