Source: http://lifehacker.com/5613900/duckcapture-is-a-screen-capture-tool-for-long-and-multi+page-documents
Windows: If you frequently find yourself trying to capture the contents of scrolling windows such as long or wide web sites, DuckCapture offers excellent capture abilities for larger-than-screen snapshots.
You'll find no shortage of screenshot tools that work just fine for snapping what is visible on the screen. DuckCapture excels by offering capturing of not only scrolling regions, like lengthy web pages, but also multi-page documents. Whether your capture region is tall, wide, or segmented into multiple pages, DuckCapture can copy the capture to your clipboard or save it as a PNG file.
DuckCapture is freeware, Windows only. Have a favorite screen capture application that offers more than basic screenshots? Let's hear about it in the comments.