A tool that I've used to great effect when explaining Internet routing to students or to lay people is Visual Route. It shows paths between a client computer and given IP addresses in a way that's much more compelling than Traceroute, including maps of the hops. This doesn't address your bulk lookup requirement, but depending on your purpose it might also be useful.  They sell several commercial versions as well as offering a free one that lacks mapping but still is graphical.

 

 

/rich