En la línea de lo expuesto antes hoy he conocido en Coindesk de la existencia de este wallet híbrido:

https://www.strongcoin.com/

A hybrid wallet allows you to send and receive Bitcoins just like any other wallet. However, the Bitcoin private key which is required to send money is encrypted in your browser before it reaches our servers.

Therefore our servers only hold encrypted private keys and neither we nor anyone else can spend your Bitcoins. Only you.

¿Alguien del foro lo ha usado?