I've updated the guide that '7p' brought us. Thanks go to 7p. This also works with my CanoScan LiDE 35 and CanoScan LiDE 50.
Guide to installing Canon CanoScan LiDE 35, 50 and 60 on Mac OS X 10.8. Mountain Lion:
FIRST PART: DELETING OLD LiDE DRIVERS AND SOFTWARE
If this is the first attempt to install the scanner, skip this part
Trash the following files/folders from these folders:
HD:/Library/Image Capture/Twain Data Sources
delete the CanoScan CanoScan XXXX.ds file
(Make note of any other files that may be in this folder.
If other files are present, move them to the desktop for now.
Then place them back after successfully using the scanner.)
HD:/Library/Preferences
delete the 'CanoScan XXXX' folder
HD:/Users/Shared
delete the folders containing the name CanoScan, or starting with CNQL.
HD:/Applications
delete the CanoScan Toolbox Application
HD:/Users/YOUR-MAC-USERNAME/Library/Preferences
delete any items named "CanoScan Toolbox"
Restart your computer, then empty the trash
SECOND PART: MAKING YOUR SCANNER WORK
Make sure your scanner is well connected
Download the right driver depending on your Model. Also download the Scanner Software. Copy the filenames and search them via Google. Make sure you download the Canon files from an official Canon domain.
CanoScan LiDE 50 and LiDE 35 work both with the 35 driver:
lide35osx7721en.dmg
CanoScan LiDE 60 driver:
lide60osx11131en.dmg
VueScan Software:
http://www.hamrick.com/#download
VueScan 9.2 (or later) x32 for Mac OS X
Alternative to VueScan: CanoScan Toolbox. I prefer VueScan.
Try your luck with Version 4 or Version 5.
CanoScan Toolbox 4: cstbosx4934ej4.dmg
CanoScan Toolbox 5: cstbosx5014ej4.dmg
Open the downloaded driver file (lide35osx7721en.dmg or lide60osx11131en.dmg)
and Double-click the ScanGear file, install and restart when prompted
Open the downloaded VueScan file (vuex3292.dmg) and drag the VueScan application to the Mac Applications folder
Open the VueScan application. The scanner should be recognized automatically.
(Alternatively try and install CanoScan Toolbox 4 or 5)