Lightscreen is a screen capture utility that helps capture and manage your screenshots. It is very comparable to FSCapture, although Lightscreen might have a few less features. For example it has 3 different methods of capture: Screen, Window, and Area (a rectangle). It also has shortkeys that are customizable (and toggle....able) for all three of the above, and for opening the program window and opening the directory.
Speaking of which, Lightscreen's main feature (since it is on the front tab, and defaultly checked on) is that it can auto-save screenshots to a file. You can choose the folder, then set the filename prefix to be anything you want, then set a suffix being either a timestamp or just a number, so that each screencap will be organized and automatically named. Or you can even swap the two, making the custom name last and the date/number first. But anyway, you can then choose either JPG, BMP, or PNG, and the delay (the amount of time before the screencap is taken.
In addition to hotkeys and auto-file saving, Lightscreen also has a ton of other options, such as an optional taskbar icon, the option to hide the Lightscreen window when screen-capping, the option to show a magnification around the mouse when using the "Area" option, the option of either a sound notification or a traytip balloon when a screencap is taken, and even a screenshot quality adjuster. It also has "Advanced" settings like showing a "Save as" dialog for every screencap, including the cursor in screencaps, and the option to "Grab" only one monitor. Oh, did I mention it has multi-monitor support?
Overall, it's a nice little screen capture program. Like I said, it is very comparable to FSCapture, even though FSCapture is lighter, smaller, and more feature filled. Lightscreen is about 5mb in size and runs at 20mb RAM for me at the moment (though I am using portable). Oh, it's also portable, hosted over at PortableApps. It is also open source, if you view the files available on SourceForge. (It being hosted there anyway should tell you that it's open source.)