Call Quality
The Android wins hands down. The speakerphone was absolutely awful on the iPhone. I imagine they have gotten better with each release, but I was so unimpressed with iPhone. By contrast, both Android devices were very impressive with their speaker phones, bluetooth connectivity, etc.
OS Speed
The iPhone wins here; Steve Jobs will do anything (including keeping Flash off any device) to keep the OS moving fast. Whereas Android slows down pretty easily. I've been told that with the advent of Android 2.2 the OS has gotten dramatically faster. But, again, I'm just using my experience.
As a MP3/Media Device
Nothing competes even closely with the iPod music player. Not even rival MP3 players like Creative or Zunes are even close. It's just brilliant; whereas the Android music player is just AWFUL! There is a good podcatcher on the Android, but they still could have spent more time putting together a decent music player.
Apps
This is a toss-up: the iPhone has better apps, but they're also ridiculously expensive. Also Apple is over-protective of their app store. I like the android productivity apps head and shoulders more than the iPhone's. But the game apps are way better for the iPhone.
As an eBook Reader
Android 2.1 has a Kindle app, and so does the iPhone. But, other eBook readers are way more available for Android. You can potentially store a lot more books on the Android as well, because the memory is expandable. I'd go with the Android.
Navigation and Multi-Apping
Hands down, Android wins. Having more than one functional button on the exterior really opens up screen space and functionality. Also, the iPhone doesn't do multi-apping unless you have an app that supports it. Call me needy, but I like listening to Pandora while texting or e-mailing.
Widgets
This is the ability to put controls/displays to apps on your home screen. It's non-existent on the iPhone! It's really easy and helpful on the Android. I've got my to-do tasks, weather, news, and other things right on my home screen. It's awesome.
Keyboard/Typing
The iPhone isn't awful and is actually decently accurate when it comes to typing. But, there is nothing that compares to a hard keyboard in my opinion. I just don't mess up in my typing as much with the hard keyboard. I also feel a lot faster and more comfortable with the hard keyboard.
Browser
The browser for iPhone wins. It just renders so much more friendly and is a lot quicker.
Parental Controls
iPhone wins. There are some work arounds for Android to make it child-safe, but there still isn't an official "Parental Controls" functionality for the Android. Shame on them.
Conclusion
I like the Android a bit more. I'll be very excited for 2.2 to get to my phone, and then I wouldn't even be writing this blog because there would be no contest.
Cheers.