In this case, files come in from my scanner to a folder, neatly numbered, and I want to convert them all to open with PPPV on a double-click.
Preview is default OSX app of choice, I guess, but as a designer, I open files with GraphicConverter, Photoshop, PaperPort Page Viewer (the 'MAXm' of the sample script) depending on need holding the control key offers me probably 30 apps that read tiffs.