They've put Linux on everything from mainframes to Sony PlayStations to PDAs; now Monta Vista Software and NEC are looking to put a stripped-down version of the operating system onto cell phones.Monta Vista, which develops an embedded version of Linux for small devices and real-time system boards, is working with NEC on a combination cell phone\/PDA device. The development was announced at last week's Consumer Electronics Show in Las Vegas, a show where Linux has been making more and more noise over the last few years. (Last year at CES, Sharp debuted its Linux-based Zaurus PDA, which combines a Blackberry-like keyboard with a PDA).NEC says it is just investigating the use of Linux in cell phones, and has no plans to announce products in the near future. Monta Vista says it is also has some other cell phone makers interested in its embedded Linux for products such as new General Packet Radio Service and 3G phones, which could be released in the Asian markets by year-end.Mobile phone applications for Linux-based PDAs have been around for several years. One of the first was from a Korean project between PalmPalm Technology, SK Telecom, and the Seoul National University, which produced the IMT-2000 Linux-enabled CDMA smart phone. Since then, Sharp also introduced a phone software that runs on its Zaurus Linux handheld.The move into the cellular handset market puts Linux up against the Symbian operating system, which is used by Nokia, Motorola, Samsung, Siemens and Sony. Monta Vista says its embedded Linux for cellphones can offer handset developers a more functional operating system at a lower cost.