The second issue that drove me nuts over the course of the week was the iPhone's poor multitasking. Or should I say the complete lack of multitasking other than phone, e-mail, and SMS data reception. Although this has been an issue for me at various other times, it was much more of a problem while covering the Expo because, as noted above, I was regularly using at least seven apps--Calendar, Phone, SMS, Mail, a Twitter app, ToDo, and iMacworld--and switching between them many times each hour. If I was viewing my list of vendors in ToDo and wanted to use iMacworld to find a vendor's booth on the show floor, that meant quitting ToDo, launching iMacworld--which was very slow to launch--and then finding the booth on the map. Then I had to quit iMacworld and launch ToDo again. A few times a day is no big deal. Hundreds of times each day was torturous. If you've seen any demos of (by the way, what's up with that name? It's like calling your product "beta"), you know that multitasking can be done well on a phone.

Next on the list was a familiar iPhone bugbear: the lack of copy-and-paste. It's normally annoying, but it was infuriating last week, as I regularly tried to get text from an e-mail message to ToDo, or an address from Calendar to Maps, or a note from ToDo to SMS. It was the first time since I've had an iPhone that the lack of copy-and-paste was more than a minor annoyance; with the iPhone as my primary computing device, not having copy-and-paste was a serious impediment to my productivity.

Finally, many an iPhone-wielding conference speaker or media member was struggling with battery life. While people have complained about battery life since the first iPhone was released back in 2007, the phone can generally get you through the day under moderate use. But under the conditions I was using it, my iPhone 3G was nearly out of juice by midday.

I wasn't alone: perhaps the most popular booth among media and speakers--in terms of where they were spending their own money--was that of , where you could buy the company's original for US$20 (normally $50) or the new-and-improved for $40 (normally $70). Indeed, a representative told me the company had sold thousands of batteries in the first two days the Expo floor was open, and I saw many iPhones connected to such batteries during meals and meetings. Granted, many people won't regularly be using their iPhone this heavily. But I've heard from many an iPhone owner who puts it through just such a ringer to and from work--for example, during an hour or two on the subway or train--every day. (This is why an external battery is one of my most-recommended iPhone accessories. If you're in the market, we'll soon publish a review roundup of such batteries.)

Laptop or iPhone?