You can get actual sliders made for the purpose. I think originally invented in australia but mainly used in south africa people are starting to use them in the north island to target kingfish off the beaches using livebaits. You can get weighted and unweighted versions, I think someone was selling them on trademe a while back. Advantage is you can cast a bare sinker as far as you can meaning you can get live or dead baits out further than you could cast even smaller baits, also means you can slide out baits that would be to big to cast. It’s called a non-return slide meaning it wont come back up the line only down.
I’ve had some for a while so plan on testing them out this summer. If you have some suitable wire you can make your own shown in this video: http://www.youtube.com/watch?v=6mvuRHpJW8k
More info here: http://www.youtube.com/watch?v=m88woeW4vHA