I would honestly love a phone in some cool color. The options in the industry are generally "boring black" and "generic white." Part of me wishes more companies would think like Nokia. Not only are the phone designs on the Lumia line very original and really cool (and sturdy as hell if you've ever used one), the color options are awesome. Neon red phone? Why not! Fluorescent yellow your thing? Sure! I really like the bright color options and, as a big fan of laguna seca blue, I'd buy the hell out of an iPhone if it came in a bright blue.
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Actually, there's research being done into plastic and composite armor for tanks. There's a whole field of infantry fighting vehicles that could greatly benefit from a material that's more impact and bullet resistant than steel or alloys but, due to its plastic nature, is much lighter. Besides, most modern tank armor is ceramic interlaced with composites anyway.
I get your point, but don't misunderestimate plastics as strong viable materials. Strong polycarb is a wonderful feeling material on a consumer electronic. Just because Samsung uses the same plastic that lego does to make their bricks doesn't mean all plastic is cheap and flimsy.