I have a Canon SD550. It takes pretty satisfying pictures, although one thing I don't like very much is the short range on the flash and zoom. I'm going to China and Eastern Europe this summer, and I was thinking that I would really like to have some good pictures. Should I upgrade to a better camera? Budget would be around $500, because I'm going to sacrifice size, I'd like a much better than 3x zoom, some image stabilization, and a nice long flash..any recommendations?