I did a little work on a inline solution with fck but i am not a js person by any means so it sort of sucked and crashed a lot of things but what i did (if you are interested ) was parse out all the html markup (duh) and then send each word to the server via ajax request and then wait for return - the return was a serialized list of suggestions if any - if there were suggestions - and this is where i cant make this work it was supposed to highlight the word and allow a drop down like a right click context menu that would replace the word if i selected one from the list

 

i used the netspell program to do it but it did all the work on the server which seemed to make it better