Dear Lifehacker, I was just wondering if you know of a way I can purchase large applications from Apple whilst on the go (away from iTunes and usually Wi-Fi). Normally the 20MB limit on 3G app downloads will stop me, which can be a pain as I keep an eye on apps when they drop in price, and if I am not near Wi-Fi or iTunes on my computer (which happens a bit) then I can miss out on some apps at a decent price. Even being able to purchase them and download later would be enough. Any ideas? Cheers, App Hungry
Dear App Hungry,
The logic of Apple imposing a limitation on what you can download via the App Store when you're on a 3G connection isn't hard to spot -- it ensures you have a better downloading experience and that you don't end up with excess data charges if you're on a really cheap plan. The likelihood of both is admittedly smaller than it used to be: 3G networks are more reliable and the download limits on iPhone-specific plans are generous enough that the odd app really shouldn't be a problem.
While the figure has changed -- it was 10MB before hitting the current 20MB ceiling -- there's no indication that Apple plans to ditch it any time soon (though Apple's secretive nature means you can't rule anything out for the future). For the present, the limitation can be annoying in the scenario you describe: there's a great special on an app, but you won't be near a Wi-Fi network until after it has run out.
The only direct option I'm aware of to solve this problem is to jailbreak your iPhone and then purchase a Cydia app called 3G Unrestrictor, which amongst its other features lets you set your iPhone to act as if it on a Wi-Fi connection even if it is actually using 3G. Not owning an iPhone, I haven't personally tested this, and you may not be comfortable with jailbreaking your device, though there are plenty of good reasons to do so.
Failing that, you need to find a Wi-Fi connection. We've covered how to locate free Wi-Fi before, and in Australia McDonald's remains the most widespread choice. Another alternative (though it eats into portability) is to carry a 3G Wi-Fi hotspot device, and connect your phone to that via Wi-Fi. That would definitely be overkill if you never used the device at any other time, but it is a way to work around the restriction. If Lifehacker readers have any other good strategies for dealing with this problem, we'd love to hear them in the comments.