You don't need it. It's recomended so you don't take up room on your device. Enjoy the phone and the site. And themes dont go on your memory card . So your okay there.
I'll post another good link at the end of this, but first... Welcome to Crackberry!
Take advantage of the very helpful BB 101. BlackBerry 101 How-To Lecture Series | CrackBerry.com . Also the powerfull search engine to dig through this bottomless pit of Crackberry knowledge for stuff already answered. Post on those existing threads or post a new one if need be. Many folks here happy to help. Some searching tips... Go To: Search Forums / Advanced Search / Key word search / search by title / "pick a key word" that comes to mind and you might stumble upon some answers and/or clues. Or search by Post content...
Launch your addiction into the next dimension. Go to wap.crackberry.com (from your phone) and install your CB Launcher.