The "Help desk talkback" script, User:Chicocvenancio/HelpDeskTBLinks.js, makes it easy to post talkback messages to users who have asked questions at the Wikipedia:Help desk and a few other help venues mentioned at the top of the script.
The script modifies the page by adding a small "TB" link after every link to a "user talk" page. When one of these links is clicked, a dialog opens. This prompts for a section name to be used in the talkback message, and standard "OK" and "Cancel" buttons.
To install the script, add this line to your common.js page:
importScript('User:Chicocvenancio/HelpDeskTBLinks.js'); // [[User:Chicocvenancio/HelpDeskTBLinks.js]]