Entity that casts light

Hey guys, does anybody knows how to make an entity that casts light, like a torch does?

I made items that did it by creating an invisible, light casting block, above the player's head  (then saving that location so it could be removed later).but yeah, it's laggy. I avoided that by only updating the block every five meters or so.

In your entity's onUpdate, you can also add something like this (in 1.7.x, at least):

int x = MathHelper.floor_double(lastTickPosX);
int y = MathHelper.floor_double(lastTickPosY);
int z = MathHelper.floor_double(lastTickPosZ);
worldObj.updateLightByType(EnumSkyBlock.Block, x, y, z);
worldObj.setLightValue(EnumSkyBlock.Block, x, y, z, 15);
worldObj.markBlockRangeForRenderUpdate(x, y, z, 12, 12, 12);

It works for the most part, but like the others have said before me, it's far from ideal in the performance realm.