Distributing OS image over WAN

Distributing OS image over WAN

Hi,
 
Do you have to install Distribution Server in dedicated server at remote site or can it be run on print or file server? Or is it even possible to install Distribution Server in Windows 7 PC? Some desktop management products can use one of the remote site client PCs as a "distribution point" for rest of the PCs at remote site, is there this kind of feature in Desktop central?
 
/Petteri