The new Nexus One is a sleek, awesome handset, but the most important ingredient in touchscreen smartphones is software. The screen is just a canvas that software paints on, and Android 2.1 is a work of art. Coming from the chunky G1, the thin and flat Nexus One hearkens back to my iPhone days. (In my pocket it doesn't make my thigh look fat, and it doesn't require a holster—it gets lots of vanity