I found this little bit code useful on the forums. It returns a list of virtual machines and their mac addresses.
<code>Get-VM | select name, @{Name="MAC"; expression={foreach($nic in (Get-View $_.ID).guest.net) {$nic.macAddress}}} </code>
Note that the forums are putting the code tags in front of and at the end of the line of code. That is not part of the actual code that you run in Powershell