As demonstrated in this video http://www.youtube.com/watch?v=CAnkOOixuDo its a fairly simple feature to add, that would be an option in the game menu, its something many many people would enjoy.
Note: Use of this Mod is against Anet rules, do NOT use it, just show your support for such a feature to be implemented officially.
Don’t take life too seriously, no one gets out alive anyway.