I taught this song to my kids last year, using the idea from Christy's Clipart (see above).  I made big shields from poster board and put on pictures from old friend magazines.  The kids learned it pretty fast.  To introduce it I drew 100 very simple stick figures on a piece of paper and made 20 copies.  Then I taped all the pages together.  I showed the kids the 1st page (hiding all the others) and told them that there were 100 men on that paper.  They thought it looked like quite a few.  Then I had some helpers come up and unfold all 20 papers and told the story about the 2000 stripling warriors.  (Idea by Nicole)