I want to do this as well, but I'm having an issue and don't know if there is a clean way around it. I'm using LimeSurvey with a custom CMS.
On the home page I added a modal iframe pop-up (not jQuery, but same idea) to ask the visitor to take the survey. If they agree they are taken to the survey page. If they decline I set a cookie, with the intent they won't be hassled with the pop-up again. I also don't want to hassle them with the pop-up if they have already completed the survey, but due to the path LimeSurvey sets in the cookie ("/survey/index.php/survey") that info is not available on the site's home page.
Other than hacking the core SurveyRuntimeHelper.php file to change the path to "/", is there a means to access the LS_$sid_STATUS cookie, or maybe another way to handle this?
I do realize that the visitor might not even accept cookies or remove them at end of session, but that's not important. What I want to do is merely intended as a convenience for most users.