A GUI to ease the process of producing a multipage PDF from a scan. gscan2pdf should work on almost any Linux/BSD machine.
Features

- Compatible with any SANE-capable scanner
- Crop, threshold & clean up scan
- Reorder pages via DND
- Write multi-page scan to PDF, DjVu or TIFF
- Write single scans to any format supported by ImageMagick
- Ocropus & tesseract support
- Place OCR output at boundary boxes supplied by Ocropus
- Incorporate PDF metadata in filename