You could stick the bolt back in partway and beat on it to see if the crank arm pops off but likely nothing will happen since the bike frame and BB weighs so much more than the arm itself. The other option is to just hacksaw down through the crank arm parallel to one of the flats. Remember that the flats are at a 45 to the axis of the arm. If you do it right you'll just graze the flat of the taper and only ruin one hacksaw blade getting both arms cut away. If not then you'll ruin two or three blades before they are off.
Truly the easy way is to get on your other bike and go for an enjoyable ride to the LBS and buy the puller. Any of the other methods I can think of are messy, need lots of tools and time and still may not actually work out. I helped someone cut away a crank arm that had a stripped out cap thread one time. We used hacksaws and chisels and it was far more work that it first appeared to be. Really, just go and get the puller. It'll avoid a lot of cussing and sweat.