Greenshot is free open-source screen capture tool that allows you to take screenshots from the whole screen area (dual screen for example), the active screen or simply selected area you want to take your screenshot.
I was a bit suspicious at first since the presentation of the tool is a bit of the same old rubbish when someone tries to sell you something completely normal but want to make it look like an innovative product but I was very surprised and happy with this tool. It really is revolutionary, light weight, allows you to edit images without the need to open paint, photoshop, gimp, illustrator or whatever application you use. It works on Windows XP and Windows Vista as far as I know.
Windows alternatives to Greenshot
