This may be the coolest Google trick to date! Doctopus runs a script in Google Drive to automate the creation of docs, hangouts, and more, plus creates a grading platform.
Though $7.99 seems steep for an app, not only does this one allow you to edit Office documents (same as Pages, Keynote, & Numbers), but it also lets you work on Google Docs.
The lite, free, version of this web service lets you create presentations and import them from either PowerPoint or Google Docs. There is also an iPad/iPhone app.