iChat2Cell for Mac

From If Then Software:

iChat2Cell is a utility that will simplify sending SMS messages through iChat. With the current way iChat allows you to send SMS messages to cellular phones, you have to first bring up a new invitation window (because Address Book doesn't save cell numbers as buddies), then you have to enter the country code and "+" and then you can finally send the message. With iChat2Cell, we take care of all those steps with one simple application. With your donation to If Then Software, we will send a code to unlock the built-in address book (you can even import your cell numbers from the Mac OS X address book) which makes it even easier to keep track and send SMS messages to your favorite cellular users — all through iChat!