I'm designing a sword-and-planet setting for my Grim Tales campaign, which will start after I wrap up my current D&D game, probably in mid-March. It is about a group of people (the PCs) who are taken near the point of their death on Earth (historical periods vary; concepts may come from the late Middle Ages up to WWII) and are sent to Samardan through some mysterious mystical means, where they undertake "John Carter of Mars/Dray Prescot of Kregen"-style adventures, saving people, making friends, marrying princesses, fighting monsters, etc.
Most of my influence comes from Ken Bulmer's work under the pseudonym of Alan Burt Akers in his tremendous Dray Prescot of Kregen series, though I'll have definite nods to the John Carter series, the Green Star series, the Gor novels, etc. It's going to be a lot of fun, I hope.

I definitely know that I'm enjoying planning it out right now.
Although most of the game will be core GT, I'm using the Mythic Earth magic system for the mystics and sorcerers of the setting, which transitions it slightly into the sword-and-sorcery realm. Still, the primary focus will be on the planetary romance genre.