Available for download is Send SMS 2.4, a new version of the Mac OS X Dashboard Widget to easily send an SMS.
User feedback for USA destinations has been improved in the case of features like Unicode SMS, Long SMS and Reply to Email.
Secondly, the widget now also supports the sequence 011 as a international prefix.

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Version 2.5p of the SMS Mac Address Book plug-in is available for Snow Leopard. SMS Mac is the Address Book plug-in to send SMS text messages.
Added feature:
Compatibility with Snow Leopard.
You can download SMS Mac 2.5p here:
http://www.smsmac.com/download/SMSMac25.dmg
Requirements: Mac OS X 10.4 and up (including Snow Leopard).