Back to School Store
In 2003, the Neopets Team was going to release a new activity on the site that relied heavily on the intelligence of your Neopet, and could even raise it! In anticipation of Neoschools, the Neopets Team released lunch boxes, erasers, notebooks, and all sorts of other supplies (that at the moment are completely worthless). However, for unknown reasons, the feature was put off, and eventually postponed indefinitely for "reasons that cannot be discussed."
It's currently unclear whether or not the Neoschool feature will ever be released, but as long as the Back to School Store is open, the potential is still there.