Make PowerShell startup blazing fast!!

If you use PowerShell...You HAVE to run this script! This will cut the time it takes PowerShell to start in half!

Function Improve-GAC { Set-Alias ngen (Join-Path ([System.Runtime.InteropServices.RuntimeEnvironment]::GetRuntimeDirectory()) ngen.exe)
 [AppDomain]::CurrentDomain.GetAssemblies() |
    sort {Split-path $_.location -leaf} |
    %{
        $Name = (Split-Path $_.location -leaf)
        if ([System.Runtime.InteropServices.RuntimeEnvironment]::FromGlobalAccessCache($_))
        {
            Write-Host "Already GACed: $Name"
        }else
        {
            Write-Host -ForegroundColor Yellow "NGENing      : $Name"
            ngen $_.location | %{"`t$_"}
         }
      }
}Improve-GAC

referance: http://blogs.msdn.com/b/powershell/archive/2007/11/08/update-gac-ps1.aspx