SolChat is billed as a “Bluetooth Solar Powered Speakerphone,” which puts it in the same general category as Iqua’s Vizor Sun, another visor-mounted speakerphone that included a solar panel as a means to passively recharge its battery in certain climates. But unlike Vizor Sun, a hulking unit with an awkward button panel, Scosche’s design is one of the smallest we’ve seen, deftly incorporating a speaker that’s as…