Samsung owners who have unlocked their device using the ChevronWP7 method should be acutely aware that when you sync your device with Zune, it gets relocked and you have to go through the unlocking procedures again. A new hack (with source code included for those who want to know how it works) prevents this from occuring.
The hack deploys to the device as a .xap using the usual sideloading methods, and uses some Samsung-specific APIs to edit the registry. There are a few additional features of the application such as removing the usual sideloading limit of 10 applications, and running Auto Data Config (ADC) to re-configure MMS/data settings. This allows MMS/Data to operate properly with other carriers. The application also has a button to reboot your device so the changes will take effect.
The application can safely be removed from your device after the changes have been committed, as they are set in the device registry which is persistent. Unfortunately as this application still relies on the ChevronWP7 unlock method, it is expected that it will cease to function when the next WP7 update is released.