The Fastest Way to Get a Site Online

Is there a python (perhaps django/flask) equivalent to this?

Not Django. Flask or Bottle maybe.

The PowerPoint example could be accomplished in any number of simple/fast ways: Dropbox comes to mind. An Apache redirect.

100% agree. Wasn't trying to imply this is the only or best way--just that it's the sort of thing you can do in <60 sec with Heroku/Sinatra.

Is Sinatra really preferable over Ramzae, Camping, etc? i.e. the other DSLs mentioned in the Heroku docs?

Yeah, I'd say it is. Sinatra is much more modern and actively developed.