The 717 goes all the way back to the early days, and IIRC was the original designation of the military versions of the 707 (either the KC135 or the E3). It fell out of use, though, and was revived when Boeing took over McDonnell Douglas. The MD-95 was renamed the Boeing 717, and the rest is literally history.
I think Olympic is the only regular European operator of the type, while AirTran, Midwest, and Hawaiian or the main US operators left (American disposed of all their ex-TWA birds). JetStar in Oz is I believe the only other operator of the type in the Pacific region (other than Hawaii).