Taking a brief look at widgetkit here is one possible solution. Using jquery you can search for any objects that have a class of slides with a child of next and click all others. The code provided below isn't tested but should point you in the right direction. As long as you don't call stop propagation or prevent default then the original click handlers should still fire.
var slideshow_count = $('.slides .next').length;var cascade_countdown = 0;$('.slides .next').each(function() { $(this).click(function() { // stop an infinite loop if we're already cascading till we've done it for all the elements. if(cascade_countdown != 0) { cascade_countdown--; return true; } // we don't include the slideshow we're clicking in this count cascade_countdown = slideshow_count - 1; var clicked_el = this; $('.slides .next').each(function() { // only click elements that aren't the initiator if(this !== clicked_el) { $(this).click(); } }); });});