First of all get the ov51x-jpeg-source_1.5.7-1_all.deb. To get it you can go to the Creatives own opensource website and follow the link from the table on the page (VF0400) or you can get it from 'http://packages.debian.org/lenny/all/ov51x-jpeg-source/download' After downloading the packet you have to install it by using dpkg as root ('sudo dpkg -i ov51x-jpeg-source_1.5.7-1_all.deb'). You can also use the svn provided by www.rastageeks.org.
At this point you have to compile the driver. But before it can be done you have to check the KDIR definition in the Makefile. It should point to the folder that contains the sources for the current kernel ('uname -r'). For me this line is 'KDIR := /usr/src/linux-source-$(shell uname -r)'. After the KDIR points to the correct folder you can issue 'make' and 'sudo make install'.
After the last command you should be able to plug the VF0400 webcam to your machine and see the blue light on it and /dev/video0 been created. A simple test that everything works is to use VLC and open capture device with it using the device '/dev/video0'. Now you should have video feed from the webcam on the screen.
All of these manuals/tutorials are provided as is. They worked for me and that is all the help I give with them, so if I forgot something or there is a typo you can inform me but do not expect me to solve your problems :) Oh and almost forgot, use them at your own risk.