Hammer and Piton( Dungeonscape, p. 45)
[Fighter Bonus Feat, Style]
You can drive pitons into your foes, giving you a useful perch from which to strike.
Climb 3 ranks, Strength 15,
While wielding a one-handed bludgeoning melee weapon in your primary hand and a climbing piton or spike in the other, you can make a touch attack with the piton as a standard action. This attack deals 1d4 points of damage + your Strength modifier. The target must be size Large or bigger. If the target is at least one size category larger than you, you can make a special Climb check (DC equal to the target's Armor Class) to enter his space as a move action. You must make the check on the same turn in which you struck your foe with the piton. If the check succeeds, you enter and remain in the target's space without provoking an attack of opportunity from the target. You lose your Dexterity bonus to Armor Class, but if your foe moves, you remain in his space as he moves, if any attack against you deals 10 or more points of damage, you must make a Climb check (DC equal to the number of points of damage) to remain in place. If the check fails, you must leave your foe's space and enter the nearest clear space.
A fighter can select Hammer and Piton as one of his fighter bonus feats (PH 38).