Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of images of handwritten, typewritten or printed text (usually captured by a scanner) into machine-editable text. (read more)
So ypu should know that there are free services that allows to upload documents in various formats and download editable version in format of their choice:
OCR Terminal (simple, fast and accurate conversion but limited to only 30 free conversions per account)
Instant OCR (multilanguage with support for more import/export formats)
P2EScan (uses Java for upload)
OnlineOCR (fast and simple, use basic text-ocr without registration)
FreeOCR (fast and simple OCR requiring no registration but can only convert to plain text)
To complete the article i cite a couple of free software that does that job: JOCR and OCR Tools
