Probably not the first person to implement this, but I wanted to make an automatic form AJAX-‘ifier’ that could capture which submit button had caused the submit event to be fired too.
It’s implemented fairly simply:
Update: As pointed out by Andrea in the comments below, this would return the value of radio and checkboxes even if they weren’t selected. I have released 0.1a and updated the link above to fix this issue. Thanks Andrea!
Update 2: I have updated this plugin, view this post for more information.
Update October 2010: I have updated this plugin for jQuery 1.4.3 as a ‘lite’ version.