Found this out when messing around with the new mana bomb.
If you unplug your ethernet (or use a macro that will lag but not dc you) and use the mana bomb on the ground like normal as if it had no cool down. When the self induced lag ends all of the places you casted the mana bomb will now lay.
Thanks.
http://imgur.com/6cELi
http://imgur.com/ApRWv
http://imgur.com/OhQmH
image is after about 20 seconds of casting. and others can see it too.