We're not usually too drawn in by the appeal of solar charging-based accessories on that aspect alone, but Eton's Rukus XL ($200) is interesting because the price seems appropriate for the size, with the solar panel simply providing extra value. Highly similar to the previously-released Soulra XL, the 14.5" x 15.6" x 11.5" triangular speaker now connects to your device using Bluetooth, and has a panel on the front that opens to reveal an elastic strap,…