Most time is spend on "waiting". So... I would seek for javascript functions that wait for page to load (on document ready) to execute or for functions that delay themselves (interval) on purpose.
Running a YSlow test on your site, I found that there are too many HTTP Requests. You load 44 different javascript files and 26 different stylesheets files. You also have 13 javascripts in the header of the page. Putting them at the footer should load the site faster.
To get more information yourself, I recommend to add the YSLOW addon at firefox. You can get it here: https://addons.mozilla.org/en-US/firefox/addon/yslow/