There are many sites on the net which offer sending free messages to anywhere in India. Infact some sites also allow sending free sms worldwide. 160by2 and mycantos are such very popular services available among others.
Most of these sites ask you to register and confirm your mobile through a code after registration. ibibo a social networking site also allows sending free sms all you have to do is confirm via imobile service.
Sites offering free sms services have character limits of less than 140 chracters and monetize their services by inserting ads.
These free sms sites can be used to promote products and services . But the best way to use these services is forward sms jokes and shayris to your own mobile. I do this often just visit a sms collection site and forward some messages to my cell to forward it to my friends. Do you use free sms services of a site?