As indicated in the comments, don't rebind your event each and every time stop() is called. Let's move that binding out, and we're also going to use stopPropgation() so that the click event won't bubble up to the document, which will trigger the plugin to start its mojo again:
function stop(){
$("#webticker").trigger('click'); //This method doesn't provide anything, except perhaps making code a bit more readable
}
$("#webticker").click(function(event){
event.stopPropagation(); //If we don't stop propagation, the click event will bubble up to the document, which will start the ticker again
$("#webticker").webTicker('stop');
if($(event.target).is('#img1')) {
$('#log').html(event.target.id + ' was clicked.');
timer = setTimeout(contin, 1);
} else if($(event.target).is('#img2')){
$('#log').html(event.target.id + ' was clicked.');
timer = setTimeout(contin, 1);
} else if($(event.target).is('#img3')){
$('#log').html(event.target.id + ' was clicked.');
timer = setTimeout(contin, 1);
} else if($(event.target).is('#img4')){
$('#log').html(event.target.id + ' was clicked.');
timer = setTimeout(contin, 1);
} else if($(event.target).is('#img5')){
$('#log').html(event.target.id + ' was clicked.');
timer = setTimeout(contin, 1);
}
});
JSFiddle: http://jsfiddle.net/rLyyR/6/
stopfunction again, and there is part of your problem. It will bind the same events over and over, and all the event handlers will be called for each binding. When you have clicked 10 times, you will have 1024 click event handlers bound to each element, and the next click will cause another 1024 bindings to be created. Click a few more times, and you will notice that the browser halts for several seconds each time, running thousands of event handlers and binding thousands of more events.