The iPhone 3G is a sell-out success, and already being hailed as another turning point in mobile design. But how does it fare against flagship phones from main rivals Nokia and Sony Ericsson?

We lined Apple’s handset up against Sony Ericsson’s 8 megapixel C905 and Nokia’s 16GB N96 to find out.

Capacity
iPhone 3G was announced with just 8GB and 16GB memory options and no card slot for extending the storage. Nokia on the other hand knows how to please an audience, with the N96 has 16GB inside, plus a microSD card slot.

Sony Ericsson’s C905 comes last in this round with 160MB of internal memory, and an M2 card slot for up to 2GB of expandable storage.

Winner: Nokia N96: 16GB plus a card slot means you’re future-proofed for years to come.

Navigation
Nokia, Apple and Sony Ericsson have all packed GPS into their new handsets, and all allow you to pin down your location, or tag photos with the place they were taken.

Nokia’s the only handset to come with proper satnav software as standard though. Its Nokia Maps software gives point-to-point directions, tons of points of interest, and even access to city guides if you find yourself far from home. There are even specific modes for pedestrians, which avoid main roads, or streets without pavements. The only downside is the fee charged for voice-prompts.

iPhone 3G meanwhile, packs Google maps, which lacks voice prompts of any kind and relies on search results to find locations. That’s fine if you know the address, but it won’t pick up every point of interest as it’s constrained to those Google knows about. On the upside, its Assisted GPS system uses Wi-Fi spots and cellular towers to determine where you are, even when there’s no GPS signal.

Much like Apple, Sony Ericsson has included Google Maps in the C905, and offers a free trial of Wayfinder Navigator satnav software, for three months. After that, you’ll need to shell out for proper voice-guided directions

Winner: Nokia N96: Its satnav software trumps Google maps for proper navigation, and it’s free!

Multimedia abilities
This is iPhone 3G’s home turf. Built around iPod technology, it’s simply the best music player out there with CoverFlow album artwork putting icing on the cake. Video playback also looks great on the 3.5″ display.

Likewise, the N96 serves up video well, and plays virtually all files from MP3 to AAC, eAAC+ and WMA, and MPEG-4 and WMV9 video. Those formats trump the iPhone 3G, which will only play files recognised by iTunes. Plus the N96 comes with DVB-H capability, which means live TV!

You’d think that by including an 8.1-megapixel camera in the C905, Sony Ericsson would include a larger display, but it’s only 2.4″. It’s fine if you’re sharing your photos via Wi-Fi to your TV though. MP3 and AAC formats are supported by the C905, and it’s also able to stream video, such as YouTube clips.

Winner: iPhone 3G: It’s music-playing abilities are second to none. It’s screen is perfect for video on the move, and it’ll even stream video from the web.

Camera
It’s a two-horse race, with both the N96 and C905 famed for their excellent cameras, and iPhone having dodgey 2.0 megapixel snapper.

At 5.0-megapixels and toting Carl Zeiss lens and an in-built flash, Nokia’s N96 can shoot video at 30fs at a 640 x 480 resolution.

The Sony Ericsson C905 on the other hand, has an 8.1-megapixel sensor, face-detection, a digital zoom of up to 16x, autofocus, BestPic, Image stabiliser, PhotoFix, Red-eye reduction, and Picture blogging.

Winner: Sony Ericsson C905: That monster sensor and face-detection make for great photos. It’s screamingly fast too.

Added extras
Announcing the iPhone 3G, Steve Jobs also detailed the new App Store, for third-party developers to upload their creations. This’ll include games, blogging software and the ability to use your iPhone as a remote control.

Nokia allows third party apps to run on its S60 operating system, giving developers a bit more freedom. We’ve already seen some awesome applications for the Symbian platform including using phones as mini-projectors and a control for a r/c car.

With its accelerometer, the C905 should be able to perform some pretty neat tricks too. It’s unclear just how much Sony Ericsson will allow you to tinker. At present, it’ll only run Java applications, which aren’t very advanced. For the time being you’ll be limited to downloading games and ringtones.

Winner: Nokia N96

Overall winner: Nokia N96

Unlike Apple’s system, Nokia doesn’t vet the applications going onto its system. It has the risk of being slightly less secure, but also allows tons more creativity and competition. It’s unlikely Apple will allow apps that directly compete with its own software, or contradict its ideals, so the choice is instantly stifled. Nokia just about wins this one.

What do you think? Vote for your favourite phone below.