kindlespark can generate SparkNotes ebooks for Kindle.
More technically, it scrapes the SparkNotes website, does some basic formatting, and uses Amazon's KindleGen to generate a .mobi file.
This was inspired by this Reddit post.
First, you need to download KindleGen.
Next, download a release of kindlespark:
(Note, I have only tested this on Mac 10.10 so far!)
These programs require you to use the command line. These instructions assume you are familiar with that environment. If you're not, sorry, I'll try to make this simpler at some point.
Find the SparkNotes URL you want to convert, for example: http://www.sparknotes.com/lit/gatsby/
Run ./kindlespark gatsby http://www.sparknotes.com/lit/gatsby/
Run ./kindlegen ./gatsby/gatsby.opf
Upload ./gatsby/gatsby.mobi to your Kindle.
GOPATH=`pwd`/gopackages/ go build kindlespark.go