I have a Canon LIDE 20 scanner, a super cheap LED flatbed scanner. I figured there was no way that it would possibly be supported under Linux. After all, none of my other scanners ever was, largely because I am so cheap I never buy SCSI scanners. But remarkably, it does work, and right out of the box with Fedora Core 2. I typed
scanimage -L and land of mercy, it found my scanner. Then a simple
scanimage --resolution 300 --mode Gray | cjpeg > foo.jpg, and voila! It works! A bit of GIMP work, and you can get the image on the right.
I also scanned an image of an ordinary quarter as a test. At 600dpi, considerable detail, some of it nearly microscopic is clearly evident.