Which OS? Apple iPhone or Google Android?

I get this question all the time: Which OS is better? Apple iPhone or Google Android?

Many medical students and physicians have asked me if they should get the Apple iPhone 4 or one of the newer Android smartphones (like the Motorola Droid, the HTC Droid Incredible, the Google Nexus One, or the Sprint Evo 4G). This question is actually several separate questions. The first question revolves around the operating system. The second question revolves around the physical form factor. The third question relates to your wireless network since iPhone is only on AT&T but Android is available on all networks.
 
Let's talk about form factor:  Some people really want a hardware QWERTY keyboard. The keyboard on the Droid isn't the best (in fact, it's probably one of its main weaknesses), but Motorola will be releasing an updated Droid that has a better keyboard.  I doubt that Apple will be releasing an iPhone Pro anytime soon that includes a hardware keyboard. 

So how about the OS? Should you go with the Apple iPhone OS? Or, should you go with Google's Android OS? This is one of those FAQs that has an evolving answer and I'm sure the answer will change. Apple's newest iPhone 4 now offers multitasking support, so you can be more productive than ever before. More medical apps are appearing on the Android Marketplace, but we still have a long way to go before we'll catch up with the iPhone's App Store. Google's Android 2.0 (now updated to 2.1 with 2.2 coming soon) includes familiar features like Google Maps with audible turn-by-turn GPS navigation, portable Wi-Fi hotspot, and more.

I'm not switching to AT&T, so I think you know which OS I'll be using.