From Robert Byrne:
Highlighted Text To File saves highlighted text to a file in the specified directory. After highlighting some text, right-click and select "Save Text to File". File names have the format "userPreference---.txt". It features optional time/date stamps in saved file name, optional dotted line separator between saves in a file, can save current page URL into saved file, preferences dialog can be shown when "Save Text to File" is clicked, text is encoded in UTF-8 (Unicode) so all international characters can be stored correctly, determines context clicked and only shows "Save to File" menu item if context is text, and ability to either append text to existing file or create a new file.
What's new in this version:
Version 1.0.13 has improved localisation support.