You can share your rage with your allies.
Prerequisites: Cha 25, greater rage class feature.
Benefit: When the character enters a rage, he or she can incite a barbarian rage in any or all allies within 60 feet. (Any ally who doesn’t wish to become enraged is unaffected.) The ally gains +4 to Strength, +4 to Constitution, and a +2 morale bonus on Will saves, but takes a –2 penalty to AC, for as long as the character remains raging. The rage of affected allies lasts a number of rounds equal to 3 + their Constitution modifier, regardless of whether they remain within 60 feet of the character. This is otherwise identical with normal barbarian rage (including the fatigue at its end).
Special: This is a mind-affecting effect.
Source: Standard Reference Document under Open Game License v1.0a, which updated this feat originally published in the Epic Level Handbook, page 60.