A power bank thinner than a phone. Five gifts, five moments of genuine surprise, and a price range wide enough that none of them feel like settling. 1. piBrick Pocket-CM5The piBrick Pocket-CM5 is the size of a smartphone and runs a full Linux desktop. Xiaomi UltraThin Magnetic Power BankThe power bank category has been stuck in the same design rut for a decade. The Xiaomi power bank isn’t a higher-capacity brick.