No, you will need to press the Menu Key and select Close/Exit. In most native applications and some third party applications, you can press and hold the escape (back) key and it will close out of applications.
__________________ The difference between stupidity and genius is that genius has its limits. When you take things for granted, the things you are granted, get taken. Even a mosquito doesn't get a pat on the back until it starts to work. Too many people miss the silver lining because they're expecting gold. [BES 5.0.3 / GroupWise 2012 HP2]