Pinger Desktop lets you send free unlimited SMS to any phone in the USA from your computer. With Pinger Desktop you get a real USA phone number for your computer. Just download Pinger Desktop to your computer. When you first sign up, select "United States" as your home country and provide a zip code. Than select a real USA phone number and start texting for free to any mobile phone number in the USA. Your friends and family in the USA can send SMS to your USA phone number without paying international fees.
You can also message anyone else on Pinger in over 200 countries. Pinger works anywhere in the world where you have Internet access. The service is ad-supported, so you will see ads from time to time. Best of all, it's free.