Currently No. 1 on /r/Bitcoin

Link: https://disposable.io/sms?nf

• Send & Receive Texts Online with disposable.io. Get a phone number and send your first message in seconds.
  
• Get any area code you want
  
• Choose to renew or dispose of your number when done.
  
• Get a temporary phone number that forwards calls to your existing line. disposable.io provides a simple web interface to send & receive SMS messages.
  
• Messages between disposable.io users are 128-bit secured end-to-end
  Optionally get text messages forwarded to your mobile device, too.
  

Perfect for craigslist, or strangers at a bar.