A PowerShell commandlet like bash's 'nl' command.

nl.ps1

Function Join-LineNumbers {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$True,
                   ValueFromPipeline=$True)]
        [string[]]$Lines
    )

    begin {
        $private:i = 1
    }

    process {
        foreach ($line in $Lines) {
            Write-Output "$private:i`t$line"
            $private:i++
        }
    }
}

Set-Alias -Name nl -Value Join-LineNumbers -Option None