If you are using an Motorola Atrix 4G and you really want an officially supported unlocked bootloader, you have to do a bit of hacking first. What you have to do is take your Atrix, find one of the leaked early builds of Gingerbread for the smartphone and install gingerbread to start with. Once Android 2.3.3 is on your smartphone getting that unlocked bootloader is a snap. This unlocked bootloader was confirmed by Motorola to be part of the final update.
If you aren't keen on having to hack your device to get Gingerbread 2.3.3 right now you can just hold out until the official update goes OTA next month. July is almost here already so it's likely only a few more weeks away. Once the official update lands, you should just be able to run the command that unlocks the bootloader courtesy of Motorola.
If you do install the leaked update the command that will unlock your hacking glory on the Atrix 4G is "fastboot oem unlock." It's worth noting that the unlock screen carries the disclaimer that unlocking your device may void your warranty. There you have it, will you wait for the official 2.3.3 update or are you installing the leaked versions and unlocking now?
[via Android Community]