Research and Development
Let's assume your script wants to share status information via a balloon message in the system tray area.
Here is a sample code to achieve that:
[system.Reflection.Assembly]::LoadWithPartialName('System.Windows.Forms') | Out-Null
$balloon = New-Object System.Windows.Forms.NotifyIcon
$path = Get-Process -id $pid | Select-Object -ExpandProperty Path
$icon = [System.Drawing.Icon]::ExtractAssociatedIcon($path)
$balloon.Icon = $icon
$balloon.BalloonTipIcon = 'Info'
$balloon.BalloonTipText = 'Completed Operation'
$balloon.BalloonTipTitle = 'Done'
$balloon.Visible = $true
$balloon.ShowBalloonTip(10000)
Note that the code uses the icon of your PowerShell application inside the tray area so the user can associate the message with the application that produced it.