Those sites allow you to set up an account and buy blocks of SMS. You can then send the messages either through their web site or through our SMS-it. You can send text, pictures and ringtones. Cost The cost per SMS is more or less the same. With the mobile phone link and the modem link you pay on a per usage, while with the internet gateway you prepay blocks of messages. Supported mobile phones SMS-it will work with all mobile phones that come with a modem driver.