All the studios are full of racks of these: http://www.funklogic.com/products.htm

Great for impressive visuals and rack cooling. :lol:

I would go for the cooling and not for having your rack stuffed. We try and leave one rack space between each piece of equipment for two reasons. One is heat the other is that some manufactures don't use toridal transformers and their transformers can radiate a lot of hum producing fields around the transformer. Since no two manufactures have their transformers in the same area the hum producing field in one unit could be over a high gain stage in another unit.

Although I am guilty of rack stuffing as well, I try (note...try) to leave spaces for ventilation as well as cleaning the layer of dust that invariable accumulates...

Remember, although minimal, that layer of dust also holds in heat.