I'll assume it's about Agile in a Flash.
As individual contributors ourselves (Tim and I move between coaching and doing often), we use the
cards to help ourselves in our day-to-day development work. We'll use the
cards as references and reminders, and stick them around in convenient places. We also will hand a card to someone else on our team and let it explain itself (so we don't have to repeat ourselves for, say, the fiftieth time on some of the pitfalls to watch out for when pairing).
Many of the cards are centered around basic practices in agile, including acceptance
test design, unit testing (via TDD), mocking, refactoring, and so on--things that should provide some immediate benefit to individual contributors. Many of the other cards will give you information about how you can best contribute to an agile team, and what a better team might look like.
Jeff