The only thing you have to do is take a photo of the document in question, using the photo tool that is part of CamScanner - PDF Creator. Of course, the photo needs to be somewhat centered and well-lit. The app will then process the photo in question, and in a matter of seconds it will have converted it to a PDF document.
Once you have the PDF document saved to your device's memory, you can work with it just like you would with any other file of this type. In addition, before saving the document, you can apply different filters to it to see if it looks better; depending on the quality of light in the photo, you might be able to obtain better results with a filter.
CamScanner - PDF Creator is an interesting tool for users who normally tend to work with printed documents, but who also want to be able to bring those documents anywhere.
Requires Android 2.3 or higher.