Cool! I just bought IDEO Method Cards. The idea is that you have a bunch of these cards that prompt you to think about the user in different ways – for example, one might ask you to imagine "A Day in the Life" where you think through the user’s day to give context for how they use your product. Another might be a "Mind map" where you brainstorm a bunch of concepts and make a diagram of how they are related to each other. This might help you group like-concepts and discover relationships between people, experiences, and emotions.
Anyway, it may be that people with a more intuitive understanding of people don’t need things like this, but for me, I tend to be a bit more on the abstract side. Hopefully this will help me get more specific in thinking about users and what they are going through in and around the product experience I’m trying to create for them.
More info on the method cards at Businessweek. I first encountered this concept while reading the excellent nerd-history-meets-methodology book Designing Interactions, written by Bill Moggridge, a co-founder of IDEO.