Opera 4 mini is good web browser for mobile phones. I’ve used it on a new prototype MOT q9 phone and 8830 black berry. It displays a website, exactly how you would see it on a computer. And it auto-zooms to the readable portions of the website, and the text is sized to fit on the screen perfectly. The text and images in the zoomed in portion are very readable on my blackberry 8830. However in the zoomed-out view, the view is too fuzzy to be useful. You can navigate if you know what you are looking for. Most phones are about 72 dpi, which contributes to the fuzzy screen. The iphone is much more useful in the zoomed out view because of the 140 DPI, and 480x640 screen.
You have be a bit careful though, the websites you visit are processed and read by a server hosted by the opera folks. I would not do any secure type of banking or ebay things with opera mini.
Watch this annoying video about iphone browser against opera mini.