The first iPhone/iPod Touch erotic game that doesn't require jailbreaking is getting a release next January. Dubbed Gift, the adult title previously got a toned down 12 years old and up PS2 version called Gift ~Prism~, obviously minus the racy content.
According to Moonstone, the game's developer, the iPhone/iPod Touch Gift will be available via the Japanese iTunes store. Even though the Moonstone producer's post says there are "event scenes," we imagine they're closer to the PS2 version's and not the original PC's. The game does use the iPhone/iPod Touch's accelerator. That could be interesting.