MotoBlur is geared towards social networking. People with multiple accounts who want to keep up with them all at once (e.g. facebook, twitter, myspace, etc.). MotoBlur just makes it easier. It's only on some of the motorola android phones. Mainly, the ones that are not as powerful as Droid (Devour, Cliq/Dext, Cliq XT, Backflip, etc.). Also, those phones are usually running Android 1.5/1.6 out of the box.