This post, FarCry Install Instructions for OS X, provides a good overview of installing FarCry on OS X when running Tomcat rather than JRun. The end result is running FarCry system with a slightly long URLs for accessing the web root (http://localhost/cfusion/myfarcry/www/index.cfm) and FarCry admin (http://localhost/cfusion/farcry_core/admin/).
It does require that Tomcat be integrated with Apache - MacDevCenter provides some excellent instructions and a precompiled mod_jk in its article Integrating Tomcat with Apache Via the mod_jk Module.