I need some advise/recommendation...I am looking to buy a new photo camera. I am a complete amateur with great ambitions to explore the world of photography, so I haven't had much exposure to different cameras. I made so research and found out that most web-sites recommend either Canon G9 or Canon PowerShot S5... I don't really know what are their differences, except that one is a bit more expensive. My budget is around $500. Which one should I get?