One of my favorite bukkit plugins allowed us to make Portcullis using some redstone and fences or iron bars. It would be amazing to be able to do that once again!

The plugin I refereed to is:

basicly you used a redstone signal to raise or lower the gate and the gate actually moved up and down. It was a great plugin for building gates to castles!

You might be able to do something like this using the Gate functionality of CraftBook.