Activate iPhone 3G with no valid sim card PLZ HELP

I restored an iPhone 3G because it got stuck on the apple logo after jailbreak process "completed"
Now the phone is restored but Im now Im stuck with the "Insert a valid SIM with no PIN lock to activate iPhone"

Is there a way to activate the iPhone without a sim card?

Yes, you'd need to hacktivate the device. This can be accomplished in many ways, depending on what version firmware you're running. What version are you running?