Mjoy is a free sms site.but d interesting part of this site is u can send massage without the link of the site displaying in the resivers phone.

HOW IS THIS POSSIBLE U MAY ASK.
Well its simple make sure d text u are typing is not more or less than 160 words(a page) and send thats all. Another interesting thing about dis site is

U CAN INCREASE(REGAIN) YOUR MONEY USED IN SENDING TEXT.
To regain the money used in sending text message in this site,after sending d message go back to the page u typed the message,reload the page and click on the banners below the send icon.u can click as many times as u want to get more money which u can use in sending more text message.
http://mjoy.com