When you retrieve results, you may want to add additional properties to the results so later you know where they came from.
Attaching additional information to complex objects works a little different than attaching them to primitive data (as described in an earlier tip).
Get-Process | Add-Member -MemberType NoteProperty -Name PC -Value $env:COMPUTERNAME -PassThru | Select-Object -Property Name, Company, Description, PC | Out-GridView
Here, the processes returned by Get-Process get an additional property called "PC" which contains the computer name where they were taken.
To view custom properties, make sure you either use Select-Object and specify the property name, or use the dot notation:
$list = Get-Process | Add-Member -MemberType NoteProperty -Name PC -Value $env:COMPUTERNAME -PassThru $list | ForEach-Object { 'Process {0} on {1}' -f $_.Name, $_.PC }