I found some sites, which are good in sending free SMS to any mobiles in India. please update your comments about those services, also add up more good ones, if any.

http://cellity.com
Install their free application in your mobile to start sending free sms. cellity works with any country, with any phone & SIM Card.

http://www.vakow.com
It’s a community of people who love SMS Forwards. You can post your SMSes and find new ones to share on phone, email or Orkut

http://160by2.com
A free sms service quite popular in india for sending free sms to any mobile phone number but it requires registration but you can send group sms to at most 10 mobile numbers ,you can also maintain phone book and lot more in this site.

Google Calender

Get the verification to register your mobile in Google Calender by following the steps below

1. Click on “Settings” at the top of any Google Calendar page, then select the “Mobile Setup” tab.
2. Select your country from the “Country” drop-down menu.
3. In the “Phone number” field, enter your phone number.
4. Select your carrier from the drop-down menu, if applicable. However, if the “See Help Center for supported providers” link is displayed, please check to see if your provider is supported before requesting your verification code.
5. If your carrier is supported, click on the “Send Verification Code” button and wait for a text message to be sent to your phone.
6. Once you receive this message, enter the code you received in your text message into the “Verification code” box and click on the “Finish setup” button.

Happy Texting!!!