Mac OS X 10.3 (Swedish): Address Book - How to Send SMS Messages Longer Than 68 Characters
Update to Mac OS X 10.3.4 or later to avoid an issue in which, when you use Address Book to send an SMS via a Bluetooth mobile phone, you can type more than sixty eight characters, but once you type the sixty ninth or greater, the message's Send button is dimmed (or "grayed out").
To send a message of up to 160 characters with the Swedish version of Mac OS X 10.3 through 10.3.3, simply press the Delete key once at the beginning of each new message.