Real Media and M-Bone feeds

>Easily. It is called cacheing. Multicasting provides exactly the
>same bandwidth savings as cacheing with cache retention time set to zero.

With the constraint that if you want to provide exactly the same
bandwidth savings, you have to have a cache at every hop. Without a
cache at every hop, there still can be significant savings, but not
quite equal to the bandwidth savings of multicast at every hop.
(Though, admittedly, multicast capable routers aren't available at every
hop either).

Except that you probably don't care about every hop either (who cares if
the 100Mbps to my access server with 4 T1's on it is partially wasted?).