Way2Sms.com used to be the number 1 website to send free SMS online. It still exists, so let us look at what they provide now.
Way2sms now offers 2 accounts, free and business. With a free account, you can send 3 SMS per day. And with a business account, you can send an SMS at 20 paise per SMS.
I believe both 160by2 and Way2sms are under the same ownership. They were a great service back in the day when SMS was still an essential thing in our lives.
Now both the companies seem to have converted into commercial services to send bulk SMS.
You can check out this for further information regarding their SMS service: Way2sms FAQ.