If you want to activate the iPhone 4 without original / supported SIM card, here is very simple solution provided by Sherif Hashim who helps the iPhone Dev Team in unlocking and jailbreaking of iPhones/iPods.
Attention – Quick Update: Don’t use this method from now, here is what Sherif Hashim posted on twitter (06 Aug 2010). The error can be now fixed by installing a Hacktivation Patch. The whole process is very simple. Head over to this post for more details. (09 Aug 2010).
It seems apple got the way phonebook sim card trick used to work fixed by hooking the activation wildcard ticket to the ICCID of the used sim. This wasn’t the case 2 days ago, and that’s why those of you who used this method recently got the “different sim detected” message. Though you will still get activated by using this method, and be able to jailbreak and unlock, but you will never be able to use your carrier SIM as it ll revert back to the non activated emergency calls screen, so I advise all to stay back of using this method for now. Those of you who used it previously to activate are good to go, but if you restored your phone again, it won’t work. And till I finish trying to figure out a way around this, if any, please stop depending on this method for now, thanks for your attention.
When you buy a new iPhone (iphone 3, 3GS or 4), you have to activate it by using the supported SIM card via iTunes. So if you don’t have the original / programmable SIM card, you can activate your iPhone by using a phonebook SIM which you use to save and transfer the contacts. These phonebook SIMs are easily available from a Phone Shop.
How to Convert standard SIM into MicroSIM by cutting:
As you know iPhone 4 does not support the standard SIMs, so you will have to cut it. You can learn here how to covert your standard SIM into a MicroSIM.
Here is the video by Hashim:
instead of telling everyone who hasn’t got the original sim that activation of the iphone is easy using a phonebook sim card, i made this video to show u all how it works , Use any phonebook sim card, they are there in radioshak, mobile phone shops or any mobile tech moles , any phone book simcard will do the trick, no need for programmable sims, all those phonebook sims used to save ur contacts and transfer them have a universal ICCIDs preprogrammed so they all work