Brachiation

(Complete Adventurer, page 106, DnD 3.5)

[General]

You can swing through trees like a monkey.

Prerequisite

Climb 4 ranks, Jump 4 ranks

Benefit

You can move through wooded areas at your base land speed, ignoring any effects on movement due to terrain. You must be at least 20 feet from the ground to use this ability. This ability works only in medium and dense forests (see page 87 of the Dungeon Master's Guide)