It's hard not to look at an iPhone and wonder whether you could chuck your laptop and use it to do all your work instead. After all, it offers e-mail, always-on Web access, and an ever increasing roster of applications, many of which have business use in mind.

Add in the fact that laptops are awkward to carry to meetings, and that their batteries never last as long as the work you need to do, and the appeal of replacing a laptop with an iPhone becomes readily apparent. So in the spirit of finding out how far you can you go relying exclusively on an iPhone for work, I decided to spend a month using an iPhone 3G in place of my laptop wherever possible. (Read about my similar BlackBerry Bold experiment.)

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Although the low likelihood of anyone ditching their laptop for an iPhone for work was confirmed, the results were somewhat surprising and definite affirmation that the iPhone’s large screen, novel gesture-based interface, built-in browser, ability to run apps, and 3G and Wi-Fi networking aren’t just for fun and games anymore.

E-mail: Almost a desktop replacement

The iPhone 3G’s version 2 OS is much more attuned to business use than Apple’s first attempt, now providing native Exchange support, as well as better security and management capabilities. If you use Exchange server or IMAP (to access your server folders), the iPhone’s e-mail capabilities are quite good. Coupled with the device's far superior ease of connectivity when compared to my laptop, iPhone e-mail quickly transformed me into an e-mail addict in places not previously possible, such as during my bus-and-train commute and pretty much anywhere I was idle. (As with the BlackBerry Bold, I had to consciously stop checking for messages to attend to other concerns, like my family.) The iPhone’s large screen also made e-mails easier to read because I didn’t have to scroll that often.

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My main frustration with iPhone e-mail is that some senders’ HTML message templates prevented me from zooming in. And the iPhone does not let you rotate messages to landscape mode for closer or wider viewing, as I would have expected. The iPhone’s support of HTML in e-mails is great -- except when it gets in the way.

As with the BlackBerry Bold, data service did leave my hands idle at times, as I waited through connectivity gaps in the train tunnels now nearly intolerable due to my newfound always-on addiction to messaging. A trip to New York also alerted me to the difficulty of single-provider coverage, as I had no data service through a whole swath of southern Manhattan, from Wall Street to Chelsea. (In the United States, the iPhone is available only through AT&T, whose coastal network coverage is inadequate.)

Switching from laptop to iPhone meant getting acquainted with the iPhone’s on-screen touch keyboard. At first, the touchpad proved hard to use, and I was constantly tapping the incorrect key. And relying on the iPhone’s autocorrect feature made for some wildly wrong substitutions. Though you can turn this feature off, the iPhone does pay attention to your typing, adjusting its autocorrection over time accordingly, making it a valuable tool in the long run. I also grew to like the iPhone’s caps-lock function and its ability to display special keyboards for symbols and accented letters -- no finger contortions or shortcut memorization required.