Sawzalls and Reciprocating Saws: HomeOwnerSupply.com
For removing large amounts of material in a hurry, whether it be wood or metal, a reciprocating saw is THE tool for the job.
The original Sawzall brand from Milwaukee is still the leader - the name has become synonomous with reciprocating saws.
I wouldn't go so far as to say every home owner should have one, but the DeWalt drill and reciprocating saw combo kit I bought when I first started working on my house has become the tool kit I reach for the most.