Screen capture software…
I find myself taking screenshots often at mostly portions of the screen; whether it is to show work in progress to others or something else. For those instance, I have been using SnagIt from TechSmith for years. This is a relatively cheap solution for performing these tasks. I loved having the ability to add arrows to the screenshot or a shadowed border that can then be immediately copied and pasted in an email or anywhere else. It is the reason I pay $49 for it. Now, if you just need to take screenshots, without any heavy editing, I have found two alternatives that come quite close.
First one is Zscreen, an open-source screen capture program for Microsoft Windows. I find this app powerful and has more option than I have use for. Including automatic uploading to ftp servers, emailing, naming conventions, silent operations and performing custom actions on any images captured.
Another, and possibly better one, is GreenShot. Very easy to use, very configurable and lightweight.