'Highly-regarded' 1966 sci-fi novelette by Zelazny. Available online.
~33 standard pages long.
First read (February 24th 2013)Edit
Online, on the computer at work and on my phone.
Came up on Reddit in January 2013 and I saw on Wikipedia that it is apparently 'highly-regarded'. On the 24th of February 2013 I didn't take a book to work so I got this up on the computer and read the first half, finishing it on the way home.
It was interesting, an interesting setting, but didn't really justify or explain why advanced machines would think or act the way they did in this story, and the fact that its protagonist was a unique AI created during a solar flare with an implied extra 'spark' of something undefined is a pretty good summary of its limited scope.