I am sorry but I speak only french and english (bad english !).
Great work your plugin is very good !
Nevertheless I see two improvement possible :
adding a removeHihghlight() function
applying the highlight ont the jQuery object fist parameter (as a first filter for highlitable elements) : jQuery("#my_element_i_want_to_hightlight").searchHighlight(option);
What do you think about that ?
Have a good day