> can anyone give me some suggestions as to how I can make 
> WinHTTrack only get the new .jpg files & the 
> (updated) .html files?
Normally this is the default behaviour. However, the update 
mechanism is tighted tot he server's update mechanism: 
httrack just asks for fresh files, and download new ones 
according to the remote server hints.

It is then possible, with bogus servers, that you 
redownload unnecessary data..