Use the Google Send to Phone service without having to install the Firefox extension. Select some text and press Ctrl+Q to use the script. You can change this key by going to
Use Tools > User Script Commands > Google Send to Phone Set Key. (Ctrl is fixed, you can change the other key).

On the Google Send to Phone page, click on the "« Back" link to arrive at the page you were in. This is because the Google Send to Phone page uses redirects, which ultimately breaks the back button.