CE can be everything from free lectures with quiz posted on dental sites, like Dentaltown, articles in journals, lectures offered by your local study club or dental society, or the aforementioned trip to the French Riviera.
I would strongly disagree with the notion that they not worth the cost, and would add that I think they are absolutely essential. Apparently most states dental boards would agree. Dental practice is rapidly evolving. From implants to materials to CAD-CAM, the way you practice will be completely different 10 years after you graduate. Take all the CE you can after dental school.