BlackBerry App World is o.k., however, if you want the opportunity to download from thousands of premium and free blackberry applications, you will want to check out the RIMarkable on-device BlackBerry AppStore.

Just point your BlackBerry device to and you will find a huge selection of BlackBerry applications and BlackBerry themes.  There are a ton free BlackBerry apps listed and premium downloads start at $0.99.

RIMarkable BlackBerry AppStore by MobiHand