The netbook battle is on. Microsoft XP — and possibly Windows 7 — are fighting it out with Linux for a place in the tiny netbook configuration. If Linux is going to beat out Microsoft as the OS of choice on netbooks, the Linux community will have to convince consumers that “costs nothing” does not mean “not worth anything.” Several vendors — including Asus, Dell, HP, Acer and MSI — are selling miniature laptops called “netbooks.” These pint-sized wonders, usually measuring about 10 inches, often feature solid-state hard drives and retail for as low as $350 to $500.