Can I use the "Scan" button with SANE? I have an HP Deskjet with integrated scanner. It has a "Scan" button on its top, but this button does not interact with the `xsane` program on my Debian machine: To get a page scanned, I have to initiate the scanning process from `xsane`. Is there a setting (or a scan program) that allows me to press the scan button and cause the program to scan a page?

If the scanner's buttons are supported by sane you can use scanbd to make them functional. You can find detailed instructions here.