I'm not trying to create persocons for perverted purposes. If I wanted to have sex with a machine I'd hump my computer. And if I had a choice between Chii and Sumomo, I'd pick Sumomo because she's too damn cute. I just want a walking, talking cell phone, dammit

But the damn toy's 6 inches tall! That's almost as big as my foot! She's only 2 inches tall in the show! @_@ They CAN make voice chips that small.. :/ At least in Japan they can.
I think it would be possible to make the basics of an android. For skin, you'd use Realdoll type skin for realism. A titanium frame would hold up the insides, and a small computer would be located in the torso. Japanese robots now are advanced enough to walk on their own, in a limited fashion. No personality though, it would be like talking to your computer.
As for mini persocons, you'd have to build it around cell phone techology, since the technology is minature enough to handle it. Phone cameras for the optical sensors, nano-technology to move the joints, and a tiny hard drive or memory chip for all the programming. But it wouldn't be nearly advanced as the real thing. And it would be damn expensive.