New York office head, Ideo 
From creating Apple's first mouse to prototyping rent-to-own toilets for low-income families in Ghana, Lee and his design firm have been identifying ways to keep ideas fresh for more than 20 years.
1. Get Your Hands Dirty
"We've become known for our human-centered approach. Core to this is spending time in the field and out of the office. When we start a new project, one of the first things we do is immerse ourselves in the actual experience of the company's product or service. If it's a running company, we sign up for a 10k race. Financial services? Open an account."
2. Expand Your Competitive Set
"Too often, companies look to define their next product or service based on their immediate competitors. But your competitive set can be a red herring. Hotel chains, for instance, should be thinking about Airbnb. You can also go beyond your industry and think about other products and services that your customers are loving, and what expectations they might create for your business."
"We now have 600 people out in the world working in 40 different disciplines, and our people bump up against each other with what they're seeing. Insight from a financial services project might spark an idea about how to get people to be proactive with their diet regimen. We've also continued this sense of cross-networking with OpenIdeo , our public online platform where we post innovation challenges."
4. Bring in Fresh Eyes
"Since we're not involved in the day-to-day of our clients' work, we can better spot opportunities that are right in front of their faces. And we can make leaps a little bit further into the future. Someone who's managing a P&L on a quarterly basis, for example, might reveal really complicated problems that she can't solve tomorrow. An external perspective can create a safe space to have that conversation."
5. Be Quick to Prototype
"Trying an idea out in small ways, no matter how rough, can get you toward launching that new idea faster. Think about what you can prototype in one minute, one hour, one day, or one week. Thankfully, large corporations are getting more comfortable with working in shorter cycles and bringing ideas to market faster."
Mark Payne, The Innovation Architect 
Divya Gugnani, The Negotiator 
David Limp, The Listener 
Karen Hershenson, The Facilitator 
Smart Talk: Justin Rattner, Anindita Mukherjee, Mary Barra, George Hu