The iPhone will likely go down as the most successful launch of any technology product in history. It's a truly revolutionary product and deserves much of the praise it has received -- but that doesn't mean it's perfect.

In the spirit of constructive criticism, we're offering up 15 big things that Apple can do in the next generation of iPhones to make using an iPhone even better. Apple hasn't said when the next-gen devices will make their appearance, but some Apple watchers have speculated early 2008.

[ See related review: The $1,975 iPod | Special report: iPhone: the revolution is here ]

In fact, we might not even have to wait for iPhone 2.0 to see some of the items on our wish list: It's conceivable that Apple could update the current crop of iPhones via software updates. Are you listening, Apple?

1. Get on the 3G train

Let's start with the most obvious shortcoming: The fact that the iPhone is tied to AT&T's old EDGE wireless data network instead of the technologically superior 3G network. One of the things that makes the iPhone revolutionary is its unprecedented use of the Internet. No other cell phone or handheld on the market offers the full-featured, Web-browsing experience of Safari mobile (to say nothing of YouTube, Maps or other Net applications).

But the EDGE data service is too slow for many Internet tasks, especially downloading large amounts of data, such as a graphically intense Web page or a video from YouTube. The iPhone's ability to use Wi-Fi instead of EDGE mitigates these limitations, but that is only an option when you're in range of a Wi-Fi network. And even though AT&T offers 3G coverage in some areas, the iPhone itself doesn't support 3G.

It isn't clear at this point how quickly AT&T plans to beef up its 3G service throughout the country. The company's Web site claims that it is working to expand 3G coverage, and its coverage indicator does show more 3G locations than when the iPhone was announced in January.

What's more, a recent patent licensing deal struck between Apple and InterDigital strongly implies that 3G support for the iPhone is in the works. (InterDigital specializes in developing embedded wireless technologies and has already developed and licensed 3G technology to other companies, including Nokia, NEC, Sharp and Panasonic.) Even if AT&T's rollout of 3G isn't speedy, 3G performance for the iPhone is still critical for its success in other markets, including Europe, which has much more widespread 3G service than the U.S.

2. Add GPS

Speaking of data services, the iPhone desperately needs GPS. Offering a dedicated Google Maps application is great, but its use is limited without GPS. After I got lost on a dark country road recently, one of my friends asked me, "How can you be lost when you've got an iPhone?" The answer, of course, is that the iPhone's Maps application is great, so long as you know where you are. If you don't, then it isn't much help.

GPS would also position the iPhone to compete with in-dash navigation devices. Think about the ability for the iPhone to be not only phone, Internet device and iPod, but also navigation system. The added value is so incredible that it really is surprising Apple didn't include GPS in the iPhone to begin with.

3. Turn auto-correct into auto-complete

There's been a good deal of criticism of the iPhone's touch-screen keyboard as compared to the physical thumb-typing keyboard common on BlackBerries and other devices. Like most people, I complained about the iPhone keyboard at first but adapted to it within a couple of weeks, though I still don't type as fast as I did on the physical keyboard of my old Treo.

Given my slower typing speed, one feature that I miss from my Treo, which ran Windows Mobile 5, is the text-autocomplete feature. True, the iPhone does have an auto-correct function. As you type, it suggests words from both a general dictionary and words that you commonly use. The more you use the feature, the more accurate it becomes; it's an essential iPhone feature.