Roam makes the SodaTop, a portable carbonator that screws onto its insulated 32-ounce bottle to turn still water into sparkling water in seconds, without a countertop machine. Designed for travel and everyday carry, the system uses recyclable steel CO2 cartridges and a triple-wall bottle that keeps drinks cold for up to 24 hours, or 48 hours with ice. Roam is currently preparing for launch through Kickstarter.