Group-Object is a great cmdlet to create lookup tables. If you wanted to identify a Windows service by its process ID, here is a way:
$serviceList = Get-WmiObject -Class Win32_Service | Group-Object -Property ProcessID -AsString -AsHashTable
Once the variable is filled, simply use the process ID as property:
PS> $serviceList.672 ExitCode : 0 Name : WSearch ProcessId : 672 StartMode : Auto State : Running Status : OK
