If you are newbie user of Blackberry, I am suggesting you to get those *right away*. I created this list basically for myself, like a "reminder", but may be somebody else would find it useful too.

• https://www.blackberry.com/beta/portals/index - Blackberry Beta Programs (includes Protect, if you are eligible member)
• http://m.google.com/sync OTA Google Calendar/Contacts
• http://m.google.com/maps - Google Maps
• http://m.google.com/voice - Google Voice
• http://m.google.com/mail - GMail
• http://www.blackberry.com/twitter/ - Twitter
• http://www.beejive.com/blackberry/ - IM
• http://mobile.yelp.com/blackberry - Yelp!
• http://foursquare.com/blackberry/beta - FourSquare
• http://www.blackberry.com/appworld/download - RIM AppWorld
• http://appworld.blackberry.com/webstore/content/760 - WeatherBug
• http://appworld.blackberry.com/webstore/content/1300 - Reboot
• http://appworld.blackberry.com/webstore/content/7259 - TripIt!
• http://www.dropbox.com/blackberry - DropBox
• http://appworld.blackberry.com/webstore/content/1565 - Calorie Counter by FatSecret
• http://www.xk72.com/midpssh/ - SSH
• http://amazon.com/kindlebb -Kindle

And other useful, but not too necessary...

• http://www.blackberry.com/gmail - Enhanced Gmail Plugin (usually already pre-insalled)
• http://logicmail.org/ota - LogicMail (w/o BB-data, over WiFi)
• http://www.linkedin.com/blackberry - LinkedIn
• http://www.blackberry.com/send/flickr - Flickr
• http://m.thetechmogul.com/ - Screenshots
• http://m.opera.com/next - Opera Mini
• http://m.cerience.com/reader/ - RepliGo Reader
• http://tripcase.com/m - TripCase
• http://appworld.blackberry.com/webstore/content/1068 - Calorie Tracker by LIVESTRONG
• http://www.ubertwitter.com/bb/download.php - Twitter

Enjoy!