zr364xx driver is included in the Linux kernel mainline since version 2.6.22
If you are lucky you just need to run "modprobe zr364xx" and start using your camera with an application like Ekiga.
If not, you should download the latest kernel source, and build it with the support for this driver.
The module is called zr364xx, and the option "CONFIG_USB_ZR364XX" to enable is located under:
Device Drivers > Multimedia devices > Video capture adapters > V4L USB devices > USB ZR364XX Camera support.
The latest code is kindly hosted by the LinuxTV project: http://linuxtv.org/hg/~ajacquet/v4l-dvb/
You can send me contributions by email.