Okay, Bryk got this whole topic going about "interesting mechanics using common components" mega-thread. He got dice and standard cards going, but I'd like to open it up to any interesting card-based mechanic...
...and I'll open it by nominating Avalon Hill's Blackbeard which earns the Tokyo Subway-Stuffer Award for cramming the following bits of information onto each card!
1. Whose turn it is in a 2-player game
2. Whose turn it is in a 3-player game
3. Whose turn it is in a 4-player game
4. Whether or not a new merchant appears (3-player only)
5. What that random event is
6. The results of a search at sea
7. Cargo value of a small ship in the North Atlantic*
8. Cargo value of a small ship in the Carribean*
9. Cargo value of a small ship off the Gold Coast*
10. Cargo value of a small ship in the Indian Ocean*
11. Cargo value of a medium ship in the North Atlantic*
12. Cargo value of a medium ship in the Carribean*
13. Cargo value of a medium ship off the Gold Coast*
14. Cargo value of a medium ship in the Indian Ocean*
15. Cargo value of a large ship in the North Atlantic*
16. Cargo value of a large ship in the Carribean*
17. Cargo value of a large ship off the Gold Coast*
18. Cargo value of a large ship in the Indian Ocean*
19. Home port of a ship in the North Atlantic*
20. Home port of a ship in the Carribean*
21. Home port of a ship off the Gold Coast*
22. Home port of a ship in the Indian Ocean*
23. Whether the cargo requires Debauchery & Revelry
24. Probability of a hostage aboard
25. Injuries sustained in combat (and game effects)
26. Which shipping lane new ships appear in
Did I miss anything?
* Yeah, okay, this is all in a table, but they're still nuggets of information.
Are these on seperate cards or one big player reference?
Each card contains all of that information. Once you know the format, it's very easy to find what you need. It's an elegant concentration of a huge amount of information on one card!