SE Hinton wrote nine books. Most of them are about teenage boys living in the dregs of society (cos she saw this in her hometown everyday). Some have been made into movies. The closest one to The Outsiders is Rumblefish. It's movie version also stars Matt Dillon, this time as Rusty-James. And Diane Lane. Apparently she preferred little known actors and once she found them she kept going back to them.
Here's a link that should help you. It's a website on all her works. link
Well, there's a book S. E. Hinton wrote called " That Was Then, This Is Now." It's kind of on the same level as Outsiders, and Ponyboy is in some of it. There is also a movie based off of it with Emilio Estevez(Two-Bit), but i haven't seen it yet.
Well there is no squeal but in the book That Was Then This IS Now, it mentions Ponyboy, Tim Shepard and Curly Shepard. but thats it. (i think!) i wish there was a squeal though!!! that would be so totally awesome!!!
Sadly there is no sequel to The Outsiders but S.E Hinton did write a book called That Was Then This is Now that does refer back to The Outsiders and has Ponyboy in part of it along with Tim and Curly Shepard. Also most of her books connect and most are about troubled teens which is awesome!!!!