Or...How I Spent My Saturday...
I had an unlocked (using iUnlock) Apple iPhone running 1.0.2, with a bunch of 3rd part apps, but I wanted the 1.1.1 update and I didn't want to lose anything, and I DID want the security fixes and new functionality Apple added in iPhone Update 1.1.1.
So..what to do?
I first spent an hour or so researching online, and then took the plunge.
Because I had SIM unlocked my iPhone using the free iUnlock utility, I needed to first "brick" my phone and "unbrick it", so let me just say, it's not a process for the meek. But here are the results: I'm SIM unlocked, on 1.1.1 and I have 95% of all my previously cool 3rd party apps running on 1.1.1. It did cost me $59 for the iPhoneSimFree utility to SIM unlock 1.1.1, but hey, cheaper than paying $4.99/minute international roaming charges, etc.
Some screenshots (aka "The Proof", as they say):
Key were the Guides at ModMyiPhone.com (the iPhone "Dev Team"'s main website. These guys are relentless and meticulous in their work, and I have to hand it to 'em, they have done a great job here.
My previous post on mod-ing the iPhone is here.
EDIT: The ONE thing I don't have back from my 1.0.2 iPhone install is the ability to create my own custom ringtones out of audio clips I already have (ie the Sesame Street "Yip Yip" aliens) but I understand there are folks working on that. iTunes 7.4.x does allow you to create/buy custom ringtones frm some music available via Apple's iTunes store, but you can't create custom ringtones via the old method that worked in 1.0.2. Currently, you can PLACE the files (.AAC, .M4A or .M4R files) in the right spot on the iPhone's OSX filesyetem, and they WILL show up in the list of available ringtones on the iPhone, but they won't actually play any sound, sadly.
But not a showstopper by any means, and again, there are folks working on that.\
EDIT #2: Ok, they've done it. There is a way to get free customized ringtones on the 1.1.1 iPohone. However, one small snag right now is that after each iTunes sync they disappear from the list of available ringtones, since iTunes (188.8.131.52 at least) re-writes the the Ringtones.plist evertime you sync (whether or not you have Ringtone sync-ing enabled). The workaround is: install the "Tapp" app that lets you run OS commands with one "tap", and after each sync run a command to copy your Ringtones.plist back. So sync, then two clicks. The Guide is here:
(I love my Sesame Street Yip Yip aliens! :)