A clever woman named Stef at the website Autostraddle (?!) has gone through IMDB and found most of the major characters in their appearances on the NBC staple, along with screen grabs from their roles. The pornstache prison guard, played by Pablo Schreiber, had a major recurring role on LAW & ORDER:SVU stalking/torturing star Mariska Hartigay's character. The only one it seems who wasn't on the show was oddly enough series star Taylor Schilling.
One of my personal favorites on the show is the mom Aleida Diaz, played by Elizabeth Rodriguez, who I directed as the spacey sister of Lauren Velez in my romantic comedy I THINK I DO. Her role on OITNB couldn't be further from her hilarious work in ITID but it's great to see her one the show in such an impressive lineup of talented ladies.