David Jackson and I share a common belief that a smart person can play the credit card game right and take advantage of credit card companies. In his TechUncovered site, David published The Radical Guide to Credit Cards, a thorough summary of how the credit card game works. It is definitely worth your 30 minutes if you feel you have not optimized your credit card usage yet.
I have to admit this Radical Guide is much more systematic than my frequent discussion of various credit card offers and tricks. In this guide, David walks you thru how credit card companies can make money from you (interests, late payment fees, balance transfer fees, cash advance fees, etc.), and how you can fight back by exploting the reward systems (get the best cards for each spending scenario). I especially like David's analysis of mileage cards. His thoughtful analysis concludes that these mileage cards are lousy deals for most people, because of the timespan to get rewarded, the multiple restrictions and the various fees associated.
(Like PFBlog, this Radical Guide is supported by context-based advertising only. If you love the Guide, please remember to pay tribute to David.)