There is a way to install and activate the most recent BETA firmware without registering the device's UDID as a developer.
What you'll need:
/System/Libraries/Core Services and find the file SystemVersion.plist| Device | Version | Build | Note |
|---|---|---|---|
| 3G | 2.2.1 | 5H11 | |
| 3G | 3.0 | 7A238j | BETA 1 |
| 3G | 3.0 | 7A259g | BETA 2 |
| 3G | 3.0 | 7A280f | BETA 3 |
| 3G | 3.0 | 7A300g | BETA 4 |
| 3G | 3.0 | 7A312g | BETA 5 |
| 3G | 3.0 | 7A341 | Final / Gold Master |
| 3G | 3.1 | 7C97d | BETA 1 |
| 3G | 3.1 | 7C106c | BETA 2 |
| 3G | 3.1 | 7C116a | BETA 3 |
In case you didn't make a backup copy, the file looks like this:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>ProductBuildVersion</key> <string>7A312g</string> <key>ProductCopyright</key> <string>1983-2009 Apple Inc.</string> <key>ProductName</key> <string>iPhone OS</string> <key>ProductVersion</key> <string>3.0</string> <key>ReleaseType</key> <string>Beta</string> </dict> </plist>