DP Review has posted a very good article about high ISO ratings, and why they're a bunch of hype. Also, I wanted to show the following comparison to people, esp. those who are constantly going on about MEGAPIXELS: What do you think will happen when you have 10 million pixels on a full-frame sensor, and then cram that many (smaller, crappier) pixels on to a 1/1.8th sensor?!?!?! Please read the article on their site, it's worth it. DP Review High ISO article.