ReplaceInPPTX.ps1

Add-type -AssemblyName office
$find = "SPEAKER"
$replace = "Jon Galloway"

function ReplaceText {
  param(
      [object]$shape,
      [string]$find,
      [string]$replace
  )

  if ($shape.HasTextFrame)
  {
     $textFrame = $shape.TextFrame
     $textRange = $textFrame.TextRange

     $textRange.Replace($find, $replace, 0, $msoFalse, $msoFalse) 
     <#
     #Use this if above replacement causes formatting to be lost.
     $paragraphs = $textRange.Paragraphs()
     foreach ($paragraph in $paragraphs)
     {
        $text = $paragraph.Text
        if($text.Contains($find)) {
            $text = $text.Replace($find, $replace)
            $paragraph.Text = $text
        }
     }
     #>
  }
}

$Application = New-Object -ComObject powerpoint.application
$msoTrue = [Microsoft.Office.Core.MsoTriState]::msoTrue
$msoFalse = [Microsoft.Office.Core.MsoTriState]::msoFalse
$application.visible = $msoTrue

$path = "C:\Users\Jon\SkyDrive\Projects\Git\"
Get-ChildItem -Path $path -Include "*.pptx" -Recurse |
ForEach-Object {
 "Modifying $_.FullName"
 #Open presentation with ReadOnly:False, Untitled:False, Visible:True
 $presentation = $application.Presentations.Open($_.fullname, $msoFalse, $msoFalse, $msoTrue)

 foreach ($slide in $presentation.Slides) {
     foreach ($shape in $slide.Shapes) {
        # [Microsoft.Office.Core.MsoShapeType]::msoGroup
        if ($shape.Type -eq 6) {
            foreach ($item in $shape.GroupItems) { 
                ReplaceText $item $find $replace
            }
        } else {
            ReplaceText $shape $find $replace
        }
    }
 } 

 $presentation.Save()
 $presentation.Close()
} 

$application.quit()
$application = $null
[gc]::collect()
[gc]::WaitForPendingFinalizers()

Why not pass a hash table into ReplaceText instead of a single find and replace value, then iterate over the collection?

@SyntaxC4 Yep. I'd like to pass the hash in to the entire script and then into ReplaceText. How would you do that?

as an [object] I guess, but doesn't it support Dictionary instead of HashTable?