No link in menu items

I’m trying to make some of my menu items without links. In other words when someone hovers they see the dropdown, but cannot click on the top link, just the dropdown links.

I’ve tried http://wordpress.org/extend/plugins/page-links-to/ but cannot seem to make it work, I’ve tried using nothing in the page links to field, http:// and nothing else, and just leaving that field blank. None seem to work.

Any ideas on how to achieve this?

Thanks
Peter