I really liked what Tim Kastelle says here. He asks us to think about what innovation is for.. something that seems left unsaid in a lot of writing on the topic. For me talk about innovation as an abstraction becomes quite grating. You can come up with all the brainstorming techniques and stage gates and whatever you like but without a connection to need or purpose, it can all get very dispiriting.
He links to this fun talk by Jane McGonigal: