GreenMountain-
the newer sparknotes. These are study guides for books. (Especially usefull for old literature where the plot is confusing. I would like to volunteer to start a "wikinotes," which summarizes the the contents of classic literature that users are likely to read in school. I think this would not be a part of wikibooks though, as it is entirely different.
Why should such summaries not be included with the relevant Wikipedia article? We have many articles about individual books or movies which go into quite a lot of detail. Presently I see no need for a spin-off.
Regards,
Erik