Updated section on Jing on 3/6/09 at 8:30 a.m. PT.
Even if you don't use a screen capture application regularly, there are good reasons to have one on standby. Instead of copying the ID number of an error message into a customer service e-mail by hand, you can quickly take and send a screen shot. Screen shots also make excellent archivers. In a click you can save an image of a flight itinerary or other receipt that you don't want to hang around in paper form. Gamers have another use case--documenting killer performance to prove their bragging rights.
Out of the expansive screenshot category, Gadwin PrintScreen is a freeware standout. It's not the newest or flashiest app, and configuring your preferences is a pain. Once you've set your preferences, however, the impressively feature-rich and completely unobtrusive app gives you a seamless experience from start to finish. While PrintScreen doesn't have its own image editor, setting up the app to automatically open the captured image in your favorite editor is a smart, painless move.
Jing is our first freeware runner-up. Its excellent pedigree shows (its publishers also make SnagIt, described below) in an inventive app that combines basic screen grabbing with the ability to record your movements on the screen. The real draw is being able to quickly and easily upload these images and screencasts to the Web, though you can e-mail images or save them locally as well. Jing's lack of an image editor is one drawback, but its annotation tools are a plus. Those who may see Jing's persistent yellow orb at the top of the screen as a distraction can also hide it and launch Jing directly from the system tray.
To go pro, the top-notch SnagIt comes with a steep price tag that's worth the clams for frequent capturers or those looking for a well-rounded app with advanced features. SnagIt's bag of tricks includes capturing multiple areas of the screen at once, taking timed snapshots, and customizing profiles. The revamped editor very usefully stores every capture you take regardless of whether you save it to disk, and lets you search captures by name or even by Website. Text capture is still ineffective (HyperSnap fared better in our tests), but the image and video tools deliver with force.
Gamers have some specialized screen capture apps at their fingertips, like the free-to-try Fraps for DirectX and OpenGL games. In addition to taking stills and video of your game in the throng of the action, Fraps will also perform some benchmarking stats, including how many frames per second flash by while you work your magic.