Review: Kyocera Zio
The Zio comes with no social networking applications pre-loaded at all. That's an odd choice for Sanyo and Cricket to make. Even so, it isn't too troublesome for Zio users to go to the Android Market and find the social networking applications of their choice.
The native Facebook and Twitter applications work just fine on the Zio, though updates would only work for me via Wi-Fi. There are dozens of alternatives available if the native apps aren't your thing.
Sanyo and Cricket have made no effort to corral social networks into a single application as other manufacturers have, and that's a good thing in my opinion. As neat as those solutions are, such as Motorola's Motoblur and HTC's Sense UI, at collecting social networking feeds, they each have their own problems.
Sometimes sticking to the basics is what works best.