What's one of the main things Apple is famous for other than all the other things you're probably thinking like Macs and iPods and Macbooks? Yes, that's right: applications. Not the Newton.
The iPhone 4 is only the start here - the phone really comes alive when you start filling it with simple to find applications.
For app-naive, the App Store has over 200,000 mini programs in the App Store portal - some are free, some cost as little as 59p, and some over £50. But the sheer range of options on offer is dizzying.
For instance, you can get a BBC iPlayer application, a camera manipulator to improve the quality of your photos, iMovie, addictive games like Angry Birds and RSS readers - all for next to nothing.
We can't really tell you how to use the application store, but go and have a nose around - the addition of iAds (which are advertising applications discreetly hidden within the apps themselves) will mean more money coming in, and therefore more applications in the future.
One of the big ones is the addition of iBooks - this turns your iPhone 4 into an eBook reader with hundreds of titles to work with.
Oddly this was one of the few areas of the phone that struggled to process quickly, as you often had to wait for the tomes to load if you want to see what's in your library.
But turning the pages is easy as pie and you can bookmark and annotate your pages as you wish - with all these features copies over the iPad and iPod touch range, so if you start reading Sherlock Holmes on your iPhone 4 you can finish it off on the larger iPad later.
Although you sound like you're probably rich enough to hire someone to read to you if you have both an iPhone 4 and iPad.
The other applications that come bundled with the iPhone 4 are pretty basic to be honest, with the Clock offering alarms and countdown timers, the compass pointing at things and the voice recorder making recordings of voices, and allowing you to share them as MMS files easily.
The Weather and Stock applications could do with being updated, if we're honest, as having to open up the application every time you want to see what's going on is a bit of a pain - that's what widgets are for.
The iPhone is only part phone, and the rest of the experience is application based - if you don't make use of all the cool things on offer, which will only grow larger as things like a higher-res camera and location-based services that can run in the background become more prevalent.
As we mentioned, the iPhone comes equipped with a compass as well as the second best representation of Google Maps we've seen on a smartphone anywhere. The phone is able to locate you via cellular towers or the GPS chip in a very quick time, meaning it becomes much harder to get lost when the compass is pointing your direction too.
Google Maps on the iPhone doesn't have the impressive feature list it does on Android, like free sat nav with Google Maps Navigation and transit maps, but it does work quickly and use pinch to zoom to move closer to the text or picture, which is a nice touch.
One of the more recent features in Google Maps for iPhone is the ability to assign a contact an address, and then direct you to their location.
You can't use Google Latitude natively on the iPhone 4, which is a shame as that kind of market penetration for a service like this could really help it take off.
You can share locations with someone via text or email though - this is really useful, and something we've used a couple of times already when trying to explain to someone where we were in London.
If only Google Maps Navigation would come to the iPhone 4, it would become an even better device - perhaps Apple has something of its own in the pipeline, as Google has said it would consider licensing the technology.