LAS VEGAS – I don’t often talk about Bluetooth speakers, but Lemon Tech caught my eye with its California Roll during Tuesday night’s CES Unveiled. That’s because it’s solar powered. It has a 5,000mAh battery in it and 32 solar cells on the back. 7 hours of sunlight will get about 20 hours of playback time. That’s handy, but it also has a USB port on it so you can use that battery to charge your mobile devices. And while you’re charging your mobile devices, it will be recharging the battery if it’s getting light. Right? So, rock on. Plus, it’s water and dust proof, making it suitable for the beach and other messy environments. It’s $249, and it ships in March. There’s a coupon code for 20% off (“5W20”), making it just under $200. It’s available in many different colors.