Firewatch, the first of Connie Willis' Oxford Time Traveller stories can be read here:
http://www.infinityplus.co.uk/stories/firewatch.htm
You could probably save it as a PDF or convert it to epub for your iPad.
It won Hugo and Nebula awards in '82.
An audio dramatization can be found here:
http://www.sffaudio.com/?p=19883
You have to scroll down the page a bit to find it.