With the release of SP2 for ISA 2004, BITS Caching is now posible. The Lazy Admin now shows you how to enable it! I have to get a new machine to install ISA 2004 on so i can play around with it. i have a virtual machine up and running, mainly for testing, but need the real box (with 2 lan connections, one to the cable modem and one to my network) before i can do proper testing!