I liked the Wishing Chair books too.
There's a new movie of The Phantom Tollbooth coming out in a couple of years, apparently. The other attempt, which I think was in the 70s, was rather hit-and-miss (though it did have the awesomeness of Mel Blanc...)
Kim: I'm detecting some weird technobabble.
Janeway: A possibly dangerous anomaly that we know nothing about?
Kim: Yeah. I suppose we should steer clear.
Janeway: Ha! Good one, Ensign. Take us in, Mr. Paris.