Feats that help accelerate special ability acquisition

[Rene Alfonso]

Just wondering if anyone knows about or if there are any feats that help a multiclass player get special class abilities that are level dependent for one of their classes. Example - a multiclass fighter/ barbarian with 10 levels of fighter and 6 of barbarian wants to get a rage power that requires barbarian level 10. Is there a feat that would allow me to use my total character level or part of my fighter level classes added to my barbarian levels for determining my effective level in being able to chose barbarian rage powers. If anyone knows of something like this can you post it here. If it does not exist then let me know also. Thank you.

[Paladin of Baha-who?]

If you retrain the fighter levels into levels of Viking then your fighter levels count as barbarian levels less 3.

[Antariuk]

Well, there is always Eldritch Heritage to pick up 1st-level abilities from sorcerer bloodlines. You need Skill Focus in the bloodline's class skill, and your effective sorcerer level for the ability is character level -2, but this is a way to pick up claws or something without having the beast totem chain.