I've had my BlackBerry Storm now since early December.  I can say I am quite happy with it.  Over the last few weeks I have found some apps that are free and great to use.

1. GMail Mobile [ OTA Download ]
   The mobile gmail app is great.  Works flawless.
2. TwitterBerry [ OTA Download ]
   BlackBerry + Twitter = Fantastic.  This app is at the top of my list.  It is lighweight and full of features.  It also has twitpic support.
3. YouTube [ OTA Download ]
   Great for killing time!  The app is real clean and makes it very easy to watch and search YouTube videos.
4. FaceBook [ OTA Download ]
   Not much in the way of features, but the basics are there.  I also like the ability to post photos directly to facebook.  Comes in handy.
5. Viigo [ OTA Download ]
   RSS, Sports Scores, Weather and much more!  This is a must download.
6. Google Maps [ OTA Download ]
   Not much needs to be said about this one.  The only feature missing is the ability to use the built-in GPS for turn-by-turn directions.
7. Soft Reset [ OTA Download ]
   Phone running slow, want to restart your Storm?  Use Soft Reset to make it happen without having to pull the battery.

I'm sure there are PLENTY of cool apps that I missed... I'll make posts as I find them.