Hi,
I have had a look and don't have a DisplayLink folder at that location (I have attached a screenshot). I am using the beta drivers for mac 1.6b2 (24548).
I have found a Dr Bott 7 port hub which states it provides true 500ma per port. The hub I have also apparently provides that but the Dr Bott one seems more convincing as it's the main selling point:
http://www.computeruniverse.net/products/e90157551.asp