One person's trash is another's treasure. The same can be said of today's scanners -- what works for some organizations might be far from adequate for others. Here's a rough guideline to help you sort through the trade-offs and buy a scanner that's best for your application.

* Device type. Here, there are three major choices -- flatbed, sheet-fed and handheld. If you need to scan large, non-standard documents or even objects, flatbed scanners are the best. They're easy to use and let you scan 3D objects in addition to magazine articles, photos and other 2D objects. Plus, objects stay still, resulting in better image quality overall. So what's the trade-off? Size. If desk space is at a premium, and especially if you plan to scan nothing more than simple documents, then a flatbed scanner may not be the optimal option.

At that point, it would be wise to consider a sheet-fed scanner. These are far smaller, taking up just a fraction of the desk space required by a flatbed. Rather than placing the object to be scanned on the flat area of a flatbed scanner, sheetfed scanners require users to slide the object through their input slot. Although they're small and provide the same quality as a flatbed, the trade-off here is that they can't scan anything but simple and usually standard-size documents and photos.

Another type of scanner to consider is the handheld. It provides for a great deal of mobility and is the top choice for salespeople and others who need to scan documents while on the road. Still, the trade-off here is that the quality is sometimes less than optimal. It requires that users drag the tool across a flat surface, such as a photo or document, and it's difficult to get good images with handheld scanners because you often have to make more than one pass across a document to capture the whole thing. But if you plan to scan on the road, handheld scanners are probably the best choice.

* Sensor type. Here there are two choices, CCD and CIS. CIS, or Contact Image Sensor, requires that the image to be captured be in contact with the sensor in order for it to produce a quality image. But the nature of scanners requires that a plate of glass always be between the sensor and the document, which can degrade the scan quality. This is usually no big deal for organizations looking to simply scan text documents, but the trade-off here is that it won't do a great job for more complex textured or 3D objects.

CCD, or Charged Coupled Device, is the better choice if high-quality scans are needed. It captures the light waves bouncing off the image being scanned, eliminating the glass plate obstruction. Still, the trade-off here is that CCD scanners are usually bulkier, heavier and pricier than their CIS counterparts.

Interface. Here there are three choices -- parallel, SCSI and USB. Parallel port scanners are the easiest to set up, but the trade-off there is that they are probably the slowest in terms of link speed. SCSI scanners are far faster, but they're far more difficult to set up. If possible, it's best to use a USB scanner. These are both simple to set up, since they simply plug into your computer, and they're fast. The trade-off here is that USB scanners tend to be pricier, but that is changing rapidly as more vendors begin rolling out USB devices.