This week's LinuxWorld Expo in San Francisco is shaping up as a showcase for <A HREF="http://www.eweek.com/article2/0,1895,2003735,00.asp?kc=EWNAVEMNL081506EOAD">Linux cellphone-related products,</A> alliances, and open source contributions. The barrage of phone-related announcements and demonstrations underscores the growing stature of Linux as a mobile phone operating system. One announcement notes that the Diffusion Group expects Linux to surpass Symbian, the current mobile phone OS marketshare leader, within four years.