But if you know someone who's getting an iPhone (or already has one and is crazy about it) and want to get them something for it, it can be difficult to know where to start. The shops are full of iPhone accessories, from the brilliant to the best-avoided.
1. Incipio Feather case - from $15
iPhone cases come in many shapes and sizes, but for everyday use, you probably won't want something that makes the slimline iPhone too bulky. Incipio's Feather cases are designed to offer protection against scratches and minor bumps, while adding only a tiny amount of extra thickness. You can get the Feather cases in dozens of colors, and for just about every model of iPhone.
2. Mophie Juice Pack Air - $79.95
The Mophie Juice Pack Air is a sleek, nicely made battery case for iPhone 4/4S that also provides a handy boost for its battery. Able to recharge an iPhone 4S to two-thirds full without adding much bulk at all, it's also finished in a nice matt plastic, making it easy to hold.
iPhone 5 users looking for a battery boost will have to look at external battery packs with USB for now – the New Trent iMP120D offers a huge amount of battery life for the price.
3. Logitech S715i - $104.99
This rechargeable iPhone and iPod dock is easily the best value speaker you'll find. The Logitech S715i's sound quality is on par with speakers more than twice its price, and it's portable, thanks to a built-in rechargeable battery.
It offers open, clear sound, with good bass detailed treble. Its dock will only work with the old, wider dock connector, so you'd need an adapter to use it with the iPhone 5, or you can opt for the slightly more pricey bluetooth version.
4. Logitech UE Boombox - $249.95
If you want a speaker that works with everything, the Logitech UE Boombox ditches the dock connector in favor of Bluetooth, so it'll work with iPhones, Android phones and even the new iPod nano. Yes, $250 is a lot to pay for a portable speaker, but it offers sound quality similar to setups that cost $100 more.
It's got booming bass, beautiful clarity in the high end, and the whole thing is made to an extremely high level of quality. If you'd rather go with something more Apple-focused, the Pure Contour 200Di Air is the best-value AirPlay speaker around at the moment.
5. Apple TV - $99
The Apple TV is almost the ultimate iOS accessory. It's a handy little box on its own, allowing you to watch movies from iTunes and Netflix, among other things. But it's a great gift for iPhone owners because those with newer devices can use it for AirPlay video streaming.
It means you can watch all sorts of content through apps on your device, a d also on the big screen. Not only that, but the iPhone 4S and iPhone 5 can mirror their screens to the Apple TV, so you can show web pages or photos, and there are games designed to take advantage of the extra screen space when using an Apple TV.
6. Fitbit Zip - $59
The Fitbit Zip isn't the most comprehensive fitness/activity tracker out there (the Nike+ FuelBand and Fitbit Ultra both offer a few extra features), but it's one of the best for getting started with keeping an eye on your fitness.
It's much cheaper than the competition, but is still a useful, hardy little unit (it's waterproof, for example), and it can sync with the iPhone 4S and 5 over Bluetooth, to give you realtime updates as to how many steps you've done over the day. It only weighs 3 ounces, too - so you'll barely notice it's there.
7. Lifeproof iPhone case - from $50
The Lifeproof iPhone case is just about the best protection you can get for an iPhone. Available for the iPhone 4/4S and 5, the Lifeproof is said to be "waterproof, dirtproof, snowproof and shockproof." It's not cheap, but it offers comprehensive protection, and it really works. It's less bulky than lots of other protective cases, too.
8. AppGear Elite CommandAR - $18
The AppGear Elite CommandAR offers something a little different for first-person shooter lovers. You attach your iPhone to the top of this plastic gun, and play an augmented-reality shooting game, requiring you to actively turn, aim and shoot your way out of trouble.
Buttons on the side let you perform actions, and you need to make the correct motion to reload. For the price, it offers something different to a console game for iPhone 4/4S owners.
9. House of Marley Redemption Song headphones - $99
The House of Marley Redemption Song headphones offer brilliant sound quality for their price, offering loads of bass as part of a rich, deep soundscape that's still beautifully balanced overall.
They're also really nicely made, with wooden backs, a fabric cable that doesn't tangle, in-line controls for answering calls, and they come with a leather and fabric carrying pouch.
10. iTunes gift card - from $10
Apple does a range of gift card and gift card packs, in all sorts of sizes, and you can now get gift apps through iTunes. iTunes gift cards let the owner spend money on music, books, movies and apps, so they're guaranteed to find something they like.
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