When I'm playing a game, I don't want Dropbox taking hogging my network connection. I have been able to noticeably reduce my latency by turning it off while playing. The same is true to a lesser extend for web browsing.
I'm looking for network equivalents for niceness and scheduling policies (
SCHED_BATCH etc. in schedtool). Does such a thing exist? Alternatively, automatically cutting off network access for a specific process while another one is running would work too.