TwitterBerry is mobile client for posting updates to Twitter. It works over the data network, so you don't need to use SMS.
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Minimum Requirements
BlackBerry OS 4.1.0+ (BlackBerry OS 4.2+ for TwitPic support)
BlackBerry Internet Browsing Service (BIS-B or BIBS) OR a BlackBerry Enterprise Server (BES) OR a direct TCP data connection
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Supported Devices
BlackBerry Storm
BlackBerry Bold
BlackBerry Curve 8900
BlackBerry Curve (8300, 8310, 8320, 8330, 8350i) Series
BlackBerry 8800 Series
BlackBerry Pearl (8100, 8110, 8120, 8130) Series
BlackBerry Pearl Flip (8220)
BlackBerry 8700 Series
BlackBerry 7130 Series
BlackBerry 7100 Series
BlackBerry 7200 Series
BlackBerry 7520