Less of a rant, more of an analysis. This is based off of the Samsung Captivate running Eclair(2.1) on the AT&T; network. You may see slight differences in other android phones. Initially, you wont notice much a difference. You lock with the button on the right side of the device. This is much like the lock button on the top. The device is unlocked by swiping, but in any direction. Navigation through interfaces is very similar.
I'm going to give a quick rundown of: the home screen, general settings, email, applications, and the market.
The home screen of the Android is similar to the iPhone's. The home screen acts more like a desktop than a list of applications. The bottom bar has your phone, email, browser, and applications buttons. Very similar to the iPhone's. You can view all of your applications by pressing the applications button on the bottom right. You can place application shortcuts and widgets on your home screen. Android's Power Controls widget allows you to quickly turn on or off your GPS, Wifi, blue tooth, and several other features. You can install shortcuts, widgets (both Android and Samsung specific), add folders, and change wallpaper by pressing and holding on the screen like you did to rearrange your apps on iPhone. I prefer the home screen with shortcuts and a separate catch all application screen to the iPhone's folders.
The keyboard on the larger screen is awesome. I can type twice as face in landscape mode. The autocorrect is a lot better than the iPhone's. My phone include a swipe keyboard. You swipe to each character then select the word on a list. I haven't used it much, but I have friends who swear by it.
The phone has four buttons on the bottom of the phone. There is a "popup" button, a back button, a home button and a search button. The popup button brings up extra options in the current application. I'd frequently press the home button on the iPhone wanting to use it as a back button. The back and home buttons on the Android phone help prevent this from happening.
The settings on the Android can be rather overwhelming. There are several more options than the iPhone. You can set what you want your phone to show up as when plugged into via USB. You can set it up to use Samsung Kies, Media Player, USB storage, or PC Internet. You can also view what applications are running in the background. One of the small frustrations with Android is that applications may still run after you close them. I've found an application that will stop all running applications and is highly customizable. It's called "Advanced Task Killer Free". It works great and saves on battery life. The absolute BEST thing is that you can simply drop an MP3 on your phone and use it as a ring, message, email, or meeting tone! Yes that means that you wont here a constant reminder tone fifteen minutes before that Monday meeting!
Setting up email on the Android is a little more advanced than the iPhone. You may have to plug in your smtp, pop, or imap settings. It's no different than setting up Yahoo or Gmail on Outlook or Thunderbird. The iPhone holds your hand and does all the work for you, but you are limited on what emails you can access on the iPhone. The Gmail application really integrates the Labels and such really well. I'd recommend using the app instead of the default email client.
Like popular video game systems, most popular applications are available on all platforms with different features. Facebook for Android doesn't have places yet, but the Twitter application on Android is far better than the iPhone's Twitter app. Androids market place is a little more difficult to navigate and find apps if you don't know what your looking for. Some applications require extra downloads for widgets. It hasn't become a big issue yet, but you can download anti-virus applications on Android phones. I use Lookout. I had a friend who purchased an application through the iPhone's market place that brute forced his iTunes password. The Android market place is less restrictive. I think you'll find a lot more interesting applications on Android, like NES emulators.