Often you have to capture the screenshots in Windows which allows you to use the PrintScreen key on your keyboard and then paste the contents in a graphics program like Microsoft Paint or GIMP. But if you want more control over your screen capture functions, then you can use the free SnapCrab utility. It can capture, save and upload the captured screenshots to your twitter or facebook pages.
You can download SnapCrab from the Fenrir Inc. website. The download is around 4 megabytes in size and available in form of a setup installer. After the installation, you can run it from its Start Menu shortcut. SnapCrab does not have any window but shows a toolbar when you launch it. This free floating toolbar can be used to capture screenshots of windows, fullscreen, top-level window or a user selected area.
The capturning functions for capturing the top-level window, selected window and fullscreen work as usual. The capturing takes place after you click on the respective buttons in the SnapCrab toolbar and then do not move your mouse cursor for three seconds. The captured snapshot is automatically copied to clipboard, saved to a specified folder or to your Windows desktop.
When you click on the Save a selected area button, your mouse cursor changes so that you can easily select the area on your screen. Just left-click and drag the cursor on your screen to select a rectangular area that you want to capture. After you are done, click on the capture button under the selected area and it would be saved to your clipboard or to a file.
If you want to capture the screen and share it on twitter, facebook or store it on Evernote, then you can click on the share button shown next to the selected area capture button. You can select whether you want to post to twitter and tweet about the picture, post it on facebook or save it on Evernote. You have to enter your twitter username and password for posting it on twitter. You can use twitter, twitpic, img.ly etc. to share the picture on twitter. If you decide to post on facebook, then it is done through your browser where you have to login to your facebook account.
In the options for SnapCrab, you can select where you want to save the picture, whether you want to open an image editor after saving, the image file format (JPEG, PNG, GIF, TIFF etc.) of the snapshot picture etc. You can select the hotkeys to be assigned for the SnapCrab program. You can choose if you want to automatically run SnapCrab with Windows. There is also an option to automatically shrink the captures to a specified width or height.
SnapCrab does not come with image editing functions like many commercial software in the same category (e.g., HyperSnap or Snagit). The lack of an image editor is a problem because most people want to edit the captured screens before sharing them with others. But it allows you to open the captured screenshots in default image editor and you can easily add GIMP or Adobe Photoshop to be fired whenever you capture a screenshot.
You can download SnapCrab from http://www.fenrir-inc.com/us/snapcrab/.