I was thinking of that earlier, it is in Players guide to Faerun, but that does not do it. Cosmo gives +skill points to three specific skills. The FRCS book does do that, however. It makes a x-class skill a class skill and gives +2 bonus.
Well, I can think of two other specific examples (both from Heroes of Battle):
Geurilla Scout adds Listen and Spot, Geurilla Warrior adds Hide and Move Silently. I think you are still limited in max ranks, but you dont pay 2 points per rank...
Jack of All Trades from Complete Adventurer, while not exactly what you are looking for, might help as well...
First level Human Paragon does that. Not a feat, I know, but one ofthe only ways I know to do it in the current ruleset. Exempler also has all skills as class skills.
I have known people to take a level in expert to max out a critical skill also.
One was the old version of Cosmopolitan from the FRCS. Pick a skill, it's a class skill and you get a +2 bonus with it. Sadly, Cosmo's been revised, and doesn't do that any longer.
The other, and still valid feat, is Versatile. Pick two skills. They are forevermore class skills for you. The feat can be taken multiple times, selecting two different skills each time. Found on page 55 of the OA Rokugan Campaign Setting book.
Skill Knowledge p81 Unearthed Arcana
Make two class skills in one of your classes a class skill for all classes (a mini Alble Learner).
Or make a single cross class skill a class skill for all classes.