The Goodyear Blimp is 80 this year and going strong. [1] Fuji's also been having good luck [2] with theirs. As for using blimps to broadcast to Cuba... that's another story. [3]

*Helium, actually.
Links:
[1] http://www.goodyearblimp.com/
[2] http://www.courant.com/business/hc-airship0821.artaug21,0,6101828.story?coll=hc-headlines-business
[3] http://www.orlandosentinel.com/news/local/state/orl-dennis2105aug21,0,3268905.story?coll=orl-news-headlines-state
[4] http://technorati.com/tag/advertising news