There is a html link type you can use for page widgets to have smartphones auto open to the SMS text messaging system.

Using the custom script and a regular html "a"  link tag, you can enter a destination of "sms:phone#" (where phone# is your destination phone number)

Example:  <a href="sms:123456789">123456789</a>

In this case the phone number text would show and would be clickable to initiate an sms text message to that phone number