The “Convert text from PDF files or images to Google Docs format” option is now available on the Google Docs file upload page:
You can upload a scanned image (JPEG, GIF, PNG) or PDF file, and Google Docs will extract the text and formatting for editing. ')
Google Docs Blog writes that the OCR system was developed in collaboration with the Google Books team. Recognition works best with high-resolution images, and not all formatting can be saved. In order to verify recognition errors, the original document is included in the new document. For now, only texts in English, French, Italian, German and Spanish are supported.