I saw a service that allows people to send free sms to any number in the world.
You can access the service from your phone.
However you need a data connection to connect. You also need to write down the number of the recipient because unlike http://www.binu.com you cant access your contacts.
However the good thing is there is nothing to download and there are no adverts that accompany sms as of now.
There is also no registration, just send your sms.
To access the service go to http://www.mfreesms.com and enjoy.