Needs review
Source: Dragon Magazine #343

Description: You can trip opponents in such a way that they fall into adjacent creatures.

Prerequisites: Improved Trip

If you successfully trip an opponent, you may forgo the immediate attack granted by Improved Trip and instead immediately make a free trip attempt against a creature adjacent to both you and the tripped opponent. This free trip attempt doesn't provoke an attack of opportunity, and if it fails, the targeted creature can react to trip you in turn. You can only attempt to trip one additional creature per round with this feat.

Special

A fighter may select Sweeping Trip as one of his fighter bonus feats.