I've just got myself a Ledger Nano S and it's pretty amazing. It's safer than keeping my private keys on a hard/USB drive as all transactions need to be approved by the device. Initialisation (mnemonic seed and PIN setup) takes place on the device itself. Jaxx integration would be great but the default Ledger Chrome apps are pretty good too. Another welcome improvement would be to allow more complex PINs as it currently allows a four digit one only (but the device resets itself after three incorrect attempts). Ah, it works with ethereum as well as bitcoin - I'm really impresed.