Available is the Send SMS Yahoo! Widget 1.6.
The Send SMS Yahoo! Widget also runs on Windows.
Version 1.6 adds several import functions. For example, you can now easily import your:

Outlook Contacts (Windows)
Address Book Contacts (Mac)
Yahoo! Address Book (Yahoo!)

It also adds the email2SMS feature which allows you to send free SMS [...]

Available is the Send SMS Dashboard Widget 1.6.
The Dashboard Send SMS widget is now Universal and is compatible with the new Intel Macs.
It also adds the email2SMS feature which allows you to send free SMS in the USA & Canada, provided you know the mobile operator of the destination mobile.
More online documentation about email2SMS.
Please send [...]

Available is SMS Mac 1.6 and eMobile 1.0.
The SMS Mac Address Book plug-in is now Universal and is compatible with the new Intel Macs.
It also adds the email2SMS feature which allows you to send free SMS in the USA & Canada, provided you know the mobile operator of the destination mobile.
More online documentation about email2SMS.
Please [...]

SMS Mac now also supports AppleScript.

The SMS Mac Scripting application allows you to send an SMS when a specific event occurs. You can use it, for example, with iCal. You can configure iCal and SMS Mac to send yourself an SMS to remind you of an important meeting. On a Mac OS X server, you [...]