Motorola has made a lot of noise about the Droid's ability to run multiple apps simultaneously. The iPhone can't do that, and often when you switch from one app to another and then back, the first app resets. The Droid easily moves among apps, but it does so in the same way as the iPhone: You have to return to the home page and select the app. I much prefer how the Palm Pre handles multiple simultaneous apps, letting you move among them through the row-of-cards metaphor, and I wish that the Android OS had something similar. Still, it does let you switch among running apps (rather than remember which apps are running when looking at the home screen) by holding the Home button, which brings up a list of currently running apps.
The iPhone, of course, shines in the amazing variety of iPhone apps. Although many are junk, there are some real gems in the App Store. The Android Market is too young to have anywhere near the selection of the Apple App Store, but I am encouraged by the number of high-quality apps that exist for the Droid and other Android devices. (Yes, there's a lot of junk, too.) And you can download apps for the Droid outside the Android Market and install them directly -- Apple gives you no such flexibility.
When using the Droid, I also miss some of the iPhone's apps-handling capabilities. For example, the iPhone lets you save Web pages as if they were apps; they display on the home screen for easy access. This feature lets me save as such an icon the Web page that tells me how long until my local bus arrives, and I don't have to wade through my browser's bookmarks to load it. On the Droid, I can't do that.
Apple's method of letting you rearrange your apps is more intuitive than the Droid's. When you select apps, they shake, and you can move them among the home screen's panes and put them where you want. If a pane is full, the iPhone moves an app to another pane to make room. On the Droid, you can move apps from the application window to your home screen's panes, but there is no visual clue that you've selected an app. Worse, if you move an app to a full home screen pane, you can't drop it onto that pane or scroll to another pane. Instead, you have to first go to the home screen pane you want, then the application window and drag the desired app to the home screen pane you previously switched to. It's the kind of rough edge you rarely see on an iPhone but crops up fairly often in the Android UI.
For business document editing, the $20 Quickoffice for iPhone lets you perform basic edits in Microsoft Word, Excel, and PowerPoint documents and retain revisions tracking in the original documents. But it doesn't work with zipped files. Apple's prohibition against saving files on the iPhone means that Quickoffice can't get to those e-mail attachments. Quickoffice does offer a cool tool to transfer files to and from the iPhone over Wi-Fi, but you need your computer up and running to do that -- in which case, why would you edit the documents on the iPhone?
There is no business-class Office editor for the Droid. The bundled Quickoffice for Android is just a viewer, and the $30 Documents to Go app from DataViz is unable to edit files sent via Exchange. It does work with files received over Gmail, but few businesses use Gmail.
I tried using Google Docs on both the iPhone and Droid, with the same results. It's barely possible to edit a spreadsheet; the most you can do is select and add rows and edit an individual cell's contents. You can't edit a text document, and for calendars all you can do is view and delete appointments.
The iPhone's copy and paste capabilities are both richer and better implemented than the Droid's. To select text on the Droid, you have to use a menu option or keyboard shortcut to turn on text selection, then tap elsewhere to stop the selection, and use another menu option or keyboard shortcut to paste. It's also hard to tell where your text cursor is on the Droid, due to its tiny, thin appearance. The iPhone, by contrast, doesn't require menus to select or deselect text, and its menus for copying, pasting, and deleting come up automatically when you select, then disappear automatically when you deselect.
On the iPhone, copying and pasting e-mail text, Web text, or Web graphics is straightforward. On the Droid, copying graphics is not supported.
Furthermore, you can copy text in e-mail on the Droid only if you are composing a message in the text-entry window; you cannot copy text in received e-mails. The Droid does detect phone numbers and addresses in e-mails, turning them into hot spots that can be clicked to launch the phone and map apps.
The winner: The iPhone, though its lack of multitasking is a major obstacle to using the huge array of available apps, and it keeps them from working together. The Droid needs more business-capable apps in its repertoire, and it must fix some of the roughness in its UI for apps handling. Its awkward cut, copy, and paste capabilities could use some work too.