I'm running VMWare Fusion on my mac (osx lion). I saved a file there that I'd like to view on the host machine. How can I access this file? VMWare is running an Ubuntu 10.04 64-bit server image.
VMWare provides a mounter for their disk image, so you can double click on the vmdk file and it should be mounted automatically.
Your real problem is that OS X has no built-in support for the ext file system, but you can easily find third party tools online. You can either download pre-compiled packages or use macport/brew to compile your own.