This extension can help you to disable compare products functionality in Magento.
Compatible with the following Magento versions: 1.4, 1.4.1.1, 1.4.2, 1.5, 1.6, 1.6.1, 1.6.2.0, 1.7, 1.8, 1.8.1, 1.9
You can install this module using Colin Mollenhour's Modman tool
$ modman init
$ modman clone https://github.com/netzkollektiv/wfs-disable-compare.git
You can update the module with this command
$ modman wfs-disable-compare
see http://www.magentocommerce.com/magento-connect/disable-compare-products.html