Yesterday, Dev-Team posted a trial fix for Push Notification System to make it work on unlocked or hacktivated iPhone’s with firmware 3.0. I have tried the fix on both iPhone 2G and iPhone 3G and can confirm that the fix is working on both like a charm!
This step by step will help you get Push notifications from the apps that can Push. You will need to have an unlocked and jailbroken iPhone for this to work.
