How about a reciprocating saw? I don't have one yet but I have a friend that loves his for sheet work.
EBay linky
Hi, I've got this, absolutely fantastic tool! Cost me about £350.
http://www.youtube.com/watch?v=d9KxebpRAYI&feature=related
.I do like the cut off function ,my £20 aldi air version doesn't do that 
