Once you've accessed the WMI and got the MAC address you can even send the value server-side if necessary.
Implications: You are connecting to the WMI (Windows Management Instrumentation) for the local machine and therefore you may have a problem if your IE security settings are restrictive. Also, this won't work in non-IE browsers; only works for Windows operating systems. Not all that restrictive then?! ;)
Troubleshooting: If you get an 'automation server can't create object' error when running the script it is probably for one of the reasons below.
- You need to enable 'Initialize and script ActiveX controls not marked as safe' on the security tab -> custom level options in IE
- WMI isn't installed correctly
- WMI isn't installed
- Some other permission issue. Are you an administrator? If on Windows 2000 server, have you installed sp4?
P.S. Another plausible option is to use an ActiveX control in connecting to WMI.