IPhone – How to get the firmware version prior to running jailbreak on a new 3GS

I jailbroke my iPhone 4 few weeks ago, specifically for the MyFi, which allows you to tether your 3G connection to your other WiFi-enabled devices (iPad, laptop, etc), without paying $20 to AT&T every month and being limited by 2Gb of data. MyFi is $19.99, but you pay it once and enjoy free tethering after that, especially if you kept your $30 unlimited data plan (I did). Initially beyond that I saw very little reason to use other apps from Cydia store, but now I slowly changing my mind, since I found few real gems.

• SBSettings - gives you quick panel to toggle WiFi, Bluetooth, 3G and few other functions. This is extremely handy, especially when you're trying to preserve your battery (long day on the conference or something) and you don't want to dive into Settings each time you want to turn WiFi on or off. SBSettings is free

• Notified Pro - this is notification management done right. Notifications have horrible usability in iOS and this app ($4.00 for Pro version, but I think they have the light one for free as well) fixes it by introducing notifications list similar to one Android has, which you can activate from status bar or via other customized shortcuts

• Frash - which is Flash for iPhone, right in your mobile Safari. Frankly I haven't use it for anything serious yet (and it doesn't support my favorite Flash game Quadradius), but it's a good app to wow your friends, since everyone knows that there's no Flash on the iPhone and you can always prove people wrong.

• My favorite app IntelliScreen - it's a paid app as well, but it's extremely handy. It gives you a highly customizable lock screen very similar to Windows Mobile's Today screen, so you can look at your calendar, emails, SMS and other info without even unlocking your phone. Really, really handy.

One other thing that I didn't try personally yet, but going to soon is sync with your PC or Mac over WiFi. I hate to do it over a cable.

Now, on the bad side:

• You have to be more careful and knowledgeable about stuff you're installing. That includes both apps (which are, in general, more buggy and may conflict with each other or with iOS) and stuff like official Apple iOS updates that you can't install unless you know that there's a jailbreak for them.

• Cydia store (and others like RockYou app store) are less informative than AppStore and quite often it's hard to figure out what certain app does

• Payment (while they allow multiple ways including AMazon payments and PayPal) is usually much more painful

• Apps quite often are more expensive (think $4.99-$9.99 range), but on the bright side they worth it

This is, unfortunately, expected behavior. Whenever you activate an iPhone (which you do as part of an OS install) it talks to Apple's servers and does various things like exchange crypto certs for APNS, etc. It also checks the IMEI of the phone to see what carrier Apple sold it to, and validates the SIM is valid for that carrier (if you buy an unlocked iPhone in a country where you can buy either locked or unlocked phones the vendor will actually copy down the IMEI number of a normal locked phone, and then enter in their system where it gets pushed to Apple's servers as an unlocked phone, there is no physical or configuration difference on the phones).

The easiest way to get it activated is (as you surmised) to use an AT&T SIM. You mentioned you have an iPhone 4, you can activate it with that SIM. There are plenty of companies that sell microSIM to SIM adapters, but if you want to do it right now you can just place the micro SIM directly in the iPhones 3GS's SIM try with tape. I would not recommend doing this on a device you intend to keep the SIM in for a an extended period because the SIM is likely to come loose (and jam the SIM tray), but if you are just inserting it, activating it, and removing it you should be fine so long as you are pretty careful with how you apply the tape and not shaking the phone too much.