If you are not a developer and still want to try iOS 5, then use this tutorial but at your own risk. Here is how to upgrade and activate the iOS 5 firmware without a developer account UDID. This iOS 5 hack was discovered Mert Erdir and exploits a security flaw in the activation screen. If you want to run the iOS 5 firmware, we recommend you to save your SHSH blobs on the iOS 4.3.3 firmware because if you encounter any error in the process you will still be able to downgrade your iPhone back to iOS 4.3.3. This method will only work for the iPhone.