Information Week has an article comparing a bunch of smartphones’ browsers at…

Smartphone Browser Shootout: Palm, BlackBerry, HTC Vs. iPhone

It’s quite a long article (6 web pages), so I’ll save you some reading and tell you the conclusion is a lot of fawning over the Apple iPhone and a bit of dissing the Treo (Palm OS version), Blackberry, and T-Mobile Wing entrants. Don’t neglect to read the comments at the bottom of one of the pages (the same comments are at the bottom of each web page). They are quite interesting themselves.
Although I don’t haver an iPhone, I am a huge admirer of it myself. But, is its browser that much better than everything else? I think it may be. I can’t speak for the non-Windows Mobile devices. But, I’ve been a huge critic of Mobile Internet Explorer for years. It has essentially not made any progress in being able to view “normal” sites (sites not reformatted for mobile devices) or even https secure sites well. Microsoft needs to take a hard look at its mobile browser if it wants to stay in the game.