We're unashamed fans of PowerShell around these parts, and here's another handy application for it: changing the way PDF files open from SharePoint document libraries that use Office Web Apps.
The Office IT Pro blog runs through how you can use PowerShell to force shared PDF documents to open in your default PDF reader, rather than in Office Web Apps (which is the default behaviour). That can be helpful on smartphones where those apps don't always behave so well.
For a similar trick, check out how to batch convert Word documents into PDF with PowerShell.
Control whether PDFs open in Word Web App or the default PDF reader [Office IT Pro Blog]