http://www.bnet.com/blog/harvard/the-one-priority-leaders-need-to-spend-time-on-but-dont/8755?promo=713&tag=nl.e713

This is great advice for many top executives, not just CEOs. Figure out the unique tasks or roles that only someone in your position in the organization can do, and farm out the less important things–even if you do them better than anyone else in the business.