iPhone OS4 / iOS on a South African iPhone... What to do!?

I heard this morning that the iOS4 upgrades are starting… The new features look FANTASTIC!

Here’s my dilema.

I have an iPhone 3GS that is unlocked so that I can use it with my MTN sim card (I have my Vodcaom sim card - a work contract that does not have a data bundle loaded) in my Motorola Milestone (a Droid for the rest of the world).

The reason for doing this is simple, I don’t want to use my work’s phone for personal browsing, facebook, twitter etc., I’d rather pay for that usage myself. Hence the decision to put my personal sim card with a data bundle into the iPhone (browsing and social networking are superb on the iPhone)!

I also tether my iPhone to my Macbook in order to access my personal email, blogs, tumblr, twitter and facebook…

If I upgrade my iPhone 3GS to iOS4 will I loose the ability to tether?

Any advice is appreciated! Remember, I am in South Africa and use my iPhone on the MTN network.

Update on Thursday, June 24, 2010 at 2:16PM by Dr Dion Forster

Well, thanks for the feedback (thanks Rowan and a few others who sent me links via twitter, facebook messages and emails).  Much appreciated!

I took the plunge and updated my iPhone 3GS to iOS 4.0 - it was quite easy! So, here's the verdict, it WORKS and it is great!

I had to jailbreak my phone using redsn0w, and then having installed Cydia I loaded the UltraSn0w repository and within minutes my phone was up and running on MTN in South Africa, with tethering enabled!

Amazingly after I had done the first install and jailbreak (which didn't allow me to unlock the phone to use on the MTN network (in fact I had to put my old AT&T sim card into the phone to activate it - the sim came with my original iPhone 1G!)  So, what I did was to restore the phone to the standard Apple firmware and then used my last backup to restore the content of my phone via iTunes (I created a backup by right clicking on the phone and selecting backup before I did the first firmware update).  That backup took about 30 minutes on the standard iPhone Apple firmware.  Once the restore was done Cydia appeared!  I couldn't believe it.  So, I looked up the UltraSn0w repository and then then installed UltraSn0w from there which unlocked the phone).

I love my iPhone! By the way, it also works on Vodacom - I tried it with my other sim card.  Just as an aside when I put the Vodacom sim card in iTunes wanted to update my carrier settings.  I'm not sure if that is safe or not, so I just cancelled it (I would hate to update the modem baseband and so disable the ability to use it on MTN)!

Standard disclaimer applies!  Try this at your own risk - if you get it wrong you may be left with a very sophisticated iPod Touch ;-)