How to find virtual machine name from a MAC address using PowerShell

Stating the obvious:
1. you need vCenter server
2. you need to be connected to your VC server from PowerShell

To get the VM name from MAC address just run this command
get-vm | Get-NetworkAdapter | where {$_.macaddress -eq "00:50:56:b4:3d:12"} | select parent,macaddress

or save this as a script i.e. get-VMfromMAC.ps1
$mac = Read-Host "What mac address do you want to lookup (format:11:22:33:44:55:66 )"
get-vm | Get-NetworkAdapter | where {$_.macaddress -eq "$mac"} | select parent,macaddress