I know o2 themselves arent unlocking the 4s as of yet, but I want to get mine unlocked quite soon, and been looking at various official IMEI unlock methods around various sites
Question is though, has anyone done this themselves? I have found a few but quite expensive (around £95-£110) but then found another site a bit cheaper, but im not sure whether its genuine or not?
Its here: iPhone 4S O2 UK Factory Unlock - United Kingdom - iPhone Factory Unlock - SoftZone Mobile Lab

Has anyone used this site, and if so is it genuine? Otherwise are there any other cheaper places you know that do IMEI unlocks?
Thanks!

Apple does not authorize legitimate unlocks of previously vendor locked phones. The only 'legitimate' way to do this is to have the carrier authorize the unlock. The places that you pay usually utilize a backdoor authorization method which is time limited and can be removed by Apple at a later date (as many people who have purchased them in the past found out the hard way, Apple *does* actually validate the data in the unlock table on a regular basis and unauthorized devices can absolutely be removed from the list!). As there is no known unlock exploit for the baseband on the 4S yet, there is no known way to soft-unlock. This means that anyone offering this is using one of several (unauthorized) ways to unlock the device that cannot be guaranteed to work forever.

It's important to recognize that if the phone is carrier locked when you get it, it can only ever be a legitimate 'factory unlocked' (that term is incorrect for what it's worth, no iPhone is unlocked at the factory, they are flagged as unlocked in the carrier database which the phone validates during initial activation, but that's just semantics) if it is unlocked by the carrier it was purchased from. Anyone advertising a 'factory unlock' that doesn't go through the carrier the phone is locked to is lying in some way and not really providing you with a carrier unlocked device after the service.

So in short term, its not really worth doing then? I've used 1 of these services in the past for an older Iphone model, and it seemed to be fine, thing is I wish I hadnt got my 4s on o2 and need an unlock as im moving to another network soon

To be completely honest -- it's a crapshoot. There are people who paid to unlock a few years ago whose phones are still working, unlocked. There are people who paid to unlock a few months ago whose unlock stopped working after a month or two. If the vendor doesn't offer any kind of warranty for it, I wouldn't risk it, it's a lot of money to set on fire.

Alternately, I'm continually called out for being too cautious -- you could go, get your phone unlocked, and never have a problem with it. It's definitely possible!

Ok, thanks for the info! I've managed to find someone who can do it for a bit cheaper anyway and is based in the UK so fingers crossed
Cheers for your help

Just like the GeveySIMs though, this requires a 112 dial, so it's illegal in the US and most countries with emergency service numbers. I don't recommend people use these methods, they're hacky and in general if you do a search through the forums, you'll find a lot of people who have complained about lack of service, failing Gevey/Turbo SIM cards, etc.

I recommend waiting until ultrasn0w is released for these basebands rather than using a SIM interposer... BUT, that's just me -- to each their own.

o2 unlock price is high in the sky and you could unlock your iPhone 4S 10 times at this price with other unlock solutions such as Gevey sim, R sim, which is also available and you could also find various verified video from Youtube...

As for the IMEI unlock, seldom hear them proof that they're not as famous as Gevey and RGKNSE sim