Working on a recent project, I ran into an issue with 1password autofill causing unexpected results with a form I'd built. I needed to know what browser events were being fired on a specific field in order to debug the problem. There are a few options here - bind an event listener in-code to every conceivable event and then log the arguments passed to the console to see what the event happened to be or better yet, just use monitorEvents.

Recent versions of webkit browsers and firebug support the monitorEvents method, which takes a DOM object as it's only argument and will spit out every event occurring on that object to the console. So you can run a bit of code like so

monitorEvents(document.getElementBy('someid'))

where someid is the id of the thing you want to monitor and you're all set without ever having to touch your own code.