A bumper crop of circumstantial evidence surrounding the Android-based PlayStation Phone is starting to come together today -- when it rains, it pours, as they say -- and one particularly interesting thread suggests that the ecosystem surrounding the device might be called "Z-System." An astute tipster notes that the term appears in the upper left of one of our shots, which maps to a domain -- z-system.com, naturally -- that's owned by Sony Ericsson. Turns out the company also holds trademarks for Z-System in the US and Benelux trademark offices (among others, presumably) that were filed (and approved) this year, and the filing category includes "software for interacting or playing with electronic or video games," not hardware, so that strongly suggests we're looking at a platform here. We suppose it's possible that this specific device will be called Z-System, but we're going to float the theory that its actually underlying gaming platform that'll bear that name -- possibly a premium game store and set of software libraries that together will earn a device the Z-System badge. As we already saw with the BlackPad / SurfBook / PlayBook fiasco, trademarks don't mean much until a device is actually announced -- but it's something to keep an eye on.