Are you ever sitting at your computer and suddenly realize you want to send someone a text message and then realize your cell phone is hidden in your purse in the other room? The Bluetooth Texter widget allows Mac users with Bluetooth set ups to connect to their Bluetooth phone and and send SMS messages.
All you have to do is activate your Dashboard, enter your message in the widget, select a phone number and hit send. The phone numbers in the widget’s drop-down list come straight from your Addressbook. The phone selection list contains your favorite paired Bluetooth phones. You can download it from Happymaking Games.
I found something comparable for PC users,
Chikka Messenger allows PC and Mac users to send text messages for free, 2-way message with friends online as well as mobile phone subscribers, send and receive MMS images and add and chat with Google talk buddies. Download Chikka from its official website.