A friend of mine recently recommended Graded Piano Repertoire
to me, so I subscribed to see what it was all about.
This site attempts to provide an alternate grading system to the main syllabuses, but by far the best thing I like about the site is the ability to find detailed information on a composition by searching their database. You can search by composer, period, level, country, pedagogical feature, form, and many more. There is even a keyword search.
The author has even gone to the trouble of locating YouTube videos of people performing the works, and uploading PDF scores of most of the pieces.
I often use my iPad during lessons, so the students can play pieces directly from the website.
Anyway, hopefully this helps a few of you out, as it has me.