A multi-purpose tool (10) is used as an air blower capable of delivering a high-velocity stream of air when in a blower mode of operation and as a rotating string trimmer capable of trimming vegetation when in a trimmer mode of operation. The tool has a blower housing (18) including an enclosed chamber (30), a plurality of vents (35) leading to the chamber, and a blower nozzle (32) for directing air from the chamber, wherein the impeller (20) is rotatably mounted in the chamber such that the housing defines an air pathway between the vents and the impeller. The multi-purpose tool also includes means (82) for blocking the flow of air between vents and the impeller when in the trimmer mode of operation and means (99, 124) for disengaging the trimmer head (22) from the internal drive shaft (26) when in the blower mode.