The Rhino Pack's 9-ounce CO2
canister fires about 250 finish nails at 90 psi—enough ammo for a few rooms' worth of crown molding (and then some). The refillable cans are also great for inflating bike tires, working atop a ladder, or for knocking out small nailing jobs that don't quite require a compressor's oomph.
Regulator: $99; spare 9-ounce tank: $24; refill: Approximately $6; all available at Lowe's
Shown with Hitachi's 16-gauge finish nailer: Approximately $180, Hitachi Power Tools