Throttle option for GNU cp

[Chris Jack]

I've been doing some large copies using cp and sometimes annoying the sys 
admins around here by using large amounts of network bandwidth. nice does not 
make any significant impact especially as I'm often running cp on a PC with 
nothing much else running.
 
Can I request that a throttle option is added to cp to allow the copy process 
to proceed more slowly and hence use less network bandwidth,
 
Regards
Chris