A plugin that sets the item in your hand as head.
BlockHead

Drop the .jar file in the plugins folder and restart you server.

BlockHead.* - Allows a player to use BlockHead (Default: op)
BlockHead.any - Allows a player to use /ashead <item name|item id> (Default: op)
BlockHead.hand - Allows a player to use /ashead (Default: op)
BlockHead.cp - Allows a player to use the BlockHead control panel (/blockhead). (Default: op)

There is no configuration!

/ashead - Sets the block in your hand as head
/ashead <item name|item id> - Sets a specified block as head
/blockhead forbid <player> <protection> - Forbids a specified player to use a command
/blockhead allow <player> - Allows a forbidden player tu use the command again
/blockhead show - Shows the forbidden players
/blockhead help | ? - Shows the help of BlockHead
/blockhead version - Shows the version of BlockHead
Aliases from /blockhead: /bh, /bhead, /blockh

Change Log

v3.0 - April 16, 2013:
- Added info text (You put on DIAMOND_BLOCK)
- Fix the player death bug
- Fixed the bug where players get the virtual item with a hard trick
- Fixed the /reload bug (BlockHead no longer crashes)
v2.0 - February 12, 2013:
- Added command /ashead <item name|item id> to set a block, even if you don't have it.
- Added control panel /blockhead (aliases: /bh, /blockh, /bhead) to forbid a specified player to use a command.
- Added permissions and removed permissions
v1.0 - February 2, 2013
- Initial Build

BlockHead v3.0