you can unlock your phone in Nigeria (or anywhere else in the world) using www.myiphoneunlocker.com i have used their software and it works a treat, also it gives you lifetime upgrades, so when apple release an updated firmware on iTunes, you can update to it, then unlock your phone again at no extra cost.
hope this helps
yes.
Yes, you can use your iPhone 3G(S) to access the Internet if you have an available WiFi connection.
YES it should although if its jailbroken/unlocked it will lock
You can't.
http://iclarified.com/entry/index.php?enid=2538
unlocked only means it can be activated on any service, not that the phone is any better, when the iphone came out it was only available on one service, unlocked means you can activate it on any service
Of course, the iPhone 3G and/or the original iPhone will take any normal sim card; the 3G iPhone will take the 3G sim as well.
You can use an internet service with your 3G provided if you are: 1) Using a 3G sim card and have your service activated 2) Are in a 3G coverage area 3) Are on an internet plan For more information, you should head to your mobile service provider.
If you unlocked your iPhone it is easy to access apps store all you need is a account to download thinks from there,if you jail braked your iPhone you may download thinks through cydia only .
Yes it will, but it will not support 3G. It works on the Edge network just fine.
Yes it is now possible to unlock all versions of iPhone 3G and 3GS
I would believe so, it can be difficult to unlock your iphone though but the iphone is exclusively at tmobile in Europe.
No You Cannot As Of Yet. I just tried it on an unlocked 3G Iphone 16 gig.