Canon S300 Are there free drivers available?
Canon has released GPL’ed driver for S300 long time ago, but not many people know about it. The website is in Japanese, but all you need is to download a couple of files. The installation guide is also in Japanese, but you just need to see how to add the filters in /etc/printcap. It also has nice GUI for configuring the printer. Note that drivers are not adapted to work with CUPS, require libpng.so.2, and are a little outdated. Note2: they updated the driver to version 2.11 (and removed 2.10).