Hidden in the downloads section of the EasyVMX! website, there is a handy little tool.

The tool is called EasyMAC (download link).

It's a tool for those who like to get further into the creation of VMware config files, and need to generate valid VMware MAC (hardware) adresses.

The tool will let you generate both random and static MAC addresses, in lower or upper case for your convenience.

EasyMAC is released under the BSD license, which means you can use it for, well, anything you like actually.