gscan2pdf is a GUI to produce PDFs or DjVus from scanned documents. Only two clicks are required to scan several pages and then save all or a slection as a PDF or DjVu file, including metadata if required.
gscan2pdf can control regular or sheet-fed(ADF) scanners with SANE with scanimage or scanadf, and can scan multiple pages at once. It presents a thumbnail view of scanned pages, and permits simple operations such as cropping, rotating and deleting pages.
OCR can be used to recognise text in the scans, and the output embedded in the PDf or DjVu.
PDF conversion is done by PDF::API2.
The resulting document can may be saved as a PDF, DjVu, multipage TIFF file, or single page image file.
Gscan2pdf is available in Ubuntu universe repository, install it via Ubuntu Software Center.