If the iPhone cat wasn't out the bag and scratching up the furniture already then Steve Jobs has finally shown us the soiled litter tray to prove. Yes, the iPhone 4 is here.

For a host of Apple-ites out there, the question isn't so much shall I get an iPhone 4 as working out how much they can sell their old one on eBay for. You people need not read on. This post is not for you. Shoo now. We're here to talk to the fence-sitters, the floating voters.

You might be looking to make the switch from feature phone to smartphone or you might have not been that impressed with the super-handset you've already got. Either way, your contract is probably up for grabs right now and you're not sure which way to jump. Should you go for the iPhone 4 or is the HTC Desire the mobile for you? Well, take a little look at our spec-off and ease your mind.

Dimensions

Winner: iPhone 4

115.2 x 58.6 x 9.3mm, 137g

Loser: HTC Desire

119 x 60 x 11.9mm, 135g

Nobody wants a fat handset weighing down their jacket on one side, making unsightly lines in one trouser pocket or taking up precious handbag space, and the battle between the two top phones here presents an interesting conundrum - is it the weight that bothers you or is it the size? While the iPhone is a shade heavier, it is considerably thinner, in fact el Jobs claims it's the thinnest smartphone in the world. 2g probably isn't that much of an issue out of the 137g weight, but 2.6mm off 11.9mm is quite a big deal. That's a tidy fit for your clothing.

Display

Winner: iPhone 4

3.5", 960 x 640, 326dpi, TFT-LCD

Loser: HTC Desire

3.7", 480 x 800, 240dpi, AMOLED

The screen is one of the most important battlegrounds when you're talking about touchscreen smartphones and the small advantage the Desire has over the iPhone is that it's bigger and not by an awful lot either. A 3.7-inch display is a significant advantage but ultimately, it pales to the quality offered by Apple - certainly on paper, anyway. The higher resolution and pixel density on the iPhone screen, and while it lacks AMOLED, that Retina display should, says Apple, replicate reading on paper, magazine paper rather than newspaper we presume.

The other point of interest is that the iPhone uses an LCD rather than an AMOLED. While the AMOLED might use less power and have arguably better video performance, it's not as good in sunlight. You can whack the brightness up to an acceptable level when you're outside but if you're having to to take a photo with the sun to you back, then you won't see a sausage.

Engine Room

Tie: iPhone 4

Apple A4 CPU, 512MB

Tie: HTC Desire

Snapdragon CPU, 576MB

Both phones have a very similar spec under the hood with 1GHz processors at the helm. While the iPhone has Apple's ARM Cortex A8, the Desire uses Qualcomm's Snapdragon platform. They're designed in different ways, but both offer the kind of performance you need in a top end-smartphone. Some might point to the additional RAM used in the Desire as an advantage but that just seems to be the extra that's needed to power the HTC Sense UI on top of Android. Of course, we might find that the A4 processor is underclocked in a way that Apple has previously done in order to save battery life in which case, we'd have to hand the category to HTC.

Battery

TIE: iPhone 4

7 hours 3G calling, 300 hours standby

Tie: HTC Desire

6.5 hours 3G calling, 360 hours standby

With a battery 16% larger than the last incarnation, technically, the the iPhone 4's battery should have the edge but, of course, it doesn't really work like that. Both batteries are the size they need to be to run the components inside them from dawn till dusk. Smartphone designers tend to be looking for a one heavy day's use on a single charge. We already know that the Desire provides this. That said, Apple are claiming a bigger battery over the 3GS and improvements with the A4 processor. That means that while it offers a longer call time (half an hour), the HTC Desire wins out on standby, 

Imaging

Winner: iPhone 4

5MP, flash, AF, 720p video capture

Loser: HTC Desire

5MP, AF, flash, 800 x 480 video capture

Neither phones are stunners for pictures and video. If you're really after a gadget for that, then look elsewhere for a smartphone or buy yourself a decent dedicated camera of some sort. That said, both handsets offer something perfectly decent. As of now, the iPhone's got itself a LED flash and better sensor and lens than the older 3GS, but what gives it the edge is the ability to capture video in 720p resolution. There also happens to be a rather nice bit of mini video editing software, iMovie for iPhone, that comes bundled too (although you'll have to pay extra). Not an area where you need to choose one phone over the other but you have to hand it to Apple here for now.

Storage

Winner: HTC DESIRE

32GB microSD + 512MB

Loser: iPHONE 4

32GB 

The HTC Desire wins this one just, mainly because while the main 32GB quota is the same the HTC Desire technically has more memory and you get the ability to swap out micro SD cards, where you can't with the iPhone. 

Software

Tie: HTC Desire

HTC Sense and Android

Tie: iPhone 4

iOS 4

Very, very hard category to judge, this one, and ultimately it's a case of horses for courses. An encyclopaedia or two has been written about the beauty and simplicity of the iPhone OS, now called iOS 4, and, now, the addition of pseudo-multitasking has added another string to its bow. All the same, you can bet your bottom dollar that there'll be a few moments of fury when you discover that your iPhone won't run the two apps at the same time that you want.

There's been enough time now for the Android Market to develop and, minus the odd exception such as Skype, it's got everything anyone could want. iPhone is certainly more intuitive and obvious and, if you were advising someone who wasn't that techy, then you'd have to suggest that that's the one for them. What Android offers is more flexibility and more scope for making the handset your own. At the same time that also means that it's possible to destroy your own user experience. Ultimately, you need to be happy to tinker if you go for Android but when you boil it down, both OSes are as good as the other.

The other bonus, of course, is that the Desire comes with the HTC Sense UI on top of the Android platform and it does an excellent job of integrating your contacts among other things. If you're into the social stuff, then it's a great way of keeping all your friends' credentials together.

Add the fact that the Desire renders Flash and it's all starting to tip one way. So, at the risk of a slew of angry comments at the bottom of this post, we're going to say that the Desire just about edges it here, but there's a more in-depth discussion needed here that we'll make sure we get into soon.

Mapping

Winner: HTC Desire

Google Maps for Navigation (UK and US only)

Loser: iPhone 4

Nav apps, but nothing on board

It's pretty simple here. You can either pay TomTom et al lots of money for turn-by-turn navigation on the iPhone or you can get Google to do it for free. It might be still in the teething stages, but it's still very good and better than all the lesser known gratis apps on the iPhone platform that offer something similar. Again, if mapping and navigation is really your thing, then you might want to be considering a Nokia.

Price

Winner: HTC Desire

Loser: iPhone 4

Swarowski-clad bling phones to one side, the iPhone 4 is the priciest kid on the block. There's no two ways about it. But then, if you were really concerned about money, you might not be looking at a top of the line smartphone anyway. You'll get better deals on the Desire. It's less, er, desirable to the masses that don't know and there just seems to be a greater degree of flexibility on the packages.

Conclusions

Choosing a phone is never a cut and dry decision for someone else to make on your behalf, but if you have to make a call on these things, then one would say that the iPhone 4 is a better phone than the HTC Desire. It's better shaped, has a better screen, you can fit more on it and, arguably, it looks better too. That doesn't mean that the HTC Desire is some kind of inferior mobile because it's not. It's just different. 90 per cent of the planet would prefer to have an iPhone 4. It will suite their needs better, but there's going to be plenty of folk out there who'd rather have the flexibility, the cheaper price and the higher level of originality that HTC, Sense and Android offer. What you have to ask yourself is which is the one for you.

Read our Apple iPhone 4 review and HTC Desire review.