My son Josh, my grandson Israel and I all packed cameras to the Portland, OR Zoo the day before Easter Sunday. I had my Canon 1D, Josh had my Canon 30D and Israel as usual preferred my Canon SD630 pocket camera.
Josh is learning DSLR photography, so a lot of my thoughts were helping him to get the most of the 30D with the Canon 100-400mm lens, while I mostly used my 70-200 f/2.8 IS lens -- not nearly as much reach!