My employer has been moving from traditional waterfall projects to a modified version of agile. Work is broken into stories, which are estimated and sequenced into two-week long iterations. Each iteration includes points for building, testing, and accepting features.
Stories are focused on testable business features. There is no way to plan and account for cross cutting concerns such as design, architecture, infrastructure, or (ironically) project management.
Should agile teams explicitly include stories or tasks for these cross-cutting concerns? How does your team handle tasks that never go away? Are they "off book"?