According to the Wirecutter — which advice I generally follow — the Canon ImageFormula P-215 is the best portable scanner. Among its attributes: a 20-page document feeder, embedded software, duplexing, and speed. The Wirecutter called it close between the P-215 and the Fujitsu ScanSnap S1300i, but gave the edge to the Canon. I got a peek at the P-215 at ABA TechShow last year, but I never managed to get a review unit from Canon. Still, the Wirecutter makes a compelling case for it.