Document scanners, with their automatic document feeders and heavy footprints, are fine for office use, where they can sit in one place and churn through paper. But they are far too clunky to use if you need to scan documents while you're on the road. That's where portable sheet-fed scanners come in. These lightweight scanners, which come in sizes ranging from deck-of-cards to box-of-crackers, are designed to scan on the go. Typically they require users to feed one sheet through at a time, and their scan quality and capabilities are limited compared to their more fully-featured desktop brethren.
In this category, the Fujitsu ScanSnap S1100 gets the best reviews. Part of the reason it's so small is that it doesn't have a document feeder or the ability to scan in duplex mode, or both sides of a page at one time. It does have a continuous feed mechanism, which allows users to continuously feed documents, and some reviews say it is quite adequate. The consensus is that its scans are fast and of very good quality for a document scanner. A proprietary driver means users can't scan from within third-party software, but with the included ScanSnap software users can scan to PDF, to a variety of Microsoft applications and to cloud services like Google Docs and Evernote. The ScanSnap S1100 is PC- and Mac-compatible. Reviewers praise the image quality on the ScanSnap S1100 compared to other portables.
For true portability, however, it's hard for any scanner to top the Xerox Mobile Scanner, which doesn't require a laptop or PC. It comes with a Wi-Fi enabled Eye-Fi memory card, which gives the scanner the ability to connect wirelessly to the Internet to transmit scans. This feature, plus the simplicity of saving directly to an SD card or USB flash drive without having the plug the scanner into either a laptop or the wall, wins praise from reviewers. A relatively new model, it has half the image resolution of the ScanSnap S1100. But if true standalone portability is a top priority, this scanner is an excellent choice, reviewers say.