Iphone 8mb 3g showing usb cable and itunes logo.

SOURCE: Iphone doesnt detect in Itunes and Usb wall charger doesnt work.

It sounds like the unlocking screwed up part of the software, if you are using the newest version, there is a problem when unlocking the phone. If you down grade to the prior software version, it may fix the problem, it's difficult to know what people have done to the phones due to the many different methods of unlocking jailbreaking etc, if it were mine I would try to do re install of the prior firmware, if that doesen't work, you may be able to just get a new sim card from your provider. That is more than likely what got messed up

SOURCE: iphone only see apple logo and itunes logo in a dark screen after

If it got wet, you can bring it to any Apple Store. Nine times out of ten they will replace it for $150 to $200 dollars. Unless they determine it is a manufacturers defect and you are still under warranty, then you want have to pay anything. they will usually just replace it for you.
Otherwise, you may have to pay up to $200 for a replacement.
Hope this helps...Let me know...
enov8

SOURCE: iphone is disabled but do not have original sim card to activate

my iphone wont respond to touch and is frozen on the screen with the usbpicture and itunes, also its not detecting sim.

SOURCE: Hi I have an iphone 3g that I unlocked and

Your phone has been relocked. It will need to be hacked again.

SOURCE: iphone 3g stuck in emergency calls only

Are you using at&t. if not it was jailbroken and unlocked and that went away after you updated it.