Studio tools that could seriously maim you: My newly acquired (pre-owned) 30" paper cutter. Looks like it could quite easily slice off an arm as well. It opens the door on the type of papers I can buy and use, since some only come in the full sheet size, and I usually make a mess of those if I try scissors. The white sheet of paper is a standard 8.5 x 11" for comparison.
I haven't exactly rationalized the cost of it or where I might be able to store it, but it was a good deal. I will use it. In fact I feel the need to chop things up right now.