Is Sony working on a PlayStation Portable/cellphone combo? From a recent U.S. Patent Office filing, we're pretty sure the company is. While the prototype represented above is full o' buttons, we're salivating at the chance of having a PSP and higher-end Sony (Ericsson?) in one device. Past pure-play gaming handsets have not been that successful (N-Gage, anyone?). But, with a popular and portable gaming platform established already, Sony may have a winner should it choose to come to market with a device like this. Note to Sony: let's try to make it a tad more successful than the last try in this space by Nokia, mkay?