also if you have an yahoo account then you can text message from there also all you have to do is where it says compose message it will be a little arrow pointing down click on it and hit SMS and then another little page will pop up and type the number in then it will tell you what to do from there. it works all the time for me.
If you have any of the newer Apple devices--running the iOS 5.01, you can both text for free to each other. For instance, if you had an iPod Touch, you can text for free to someone with: an iPad 2, an iPhone or another iPod. Also from/to a Mac computer running iOS 5, to any of those devices above.