What we need is to know when a number has been ported to another rate center (and thus the LRN is a new rate center and we are charged differently).
I don't see anywhere on that site to put in a full USA number, only NPA/NXX.
There is one place -
http://www.callwithus.com/API#lrn that does LRN lookups for .0003. I can pretty easily see creating a script to cache the results and only check before calling a new number. Also, grn/ezcall logs can be harvested - after the fact.
With both of these together - is it possible to group together to maintain a list, automatically? e.g. the script that looks up will also submit to one of our DBs. There's local caching, coding issue, conflict resolution, cache age, and infrastructure which makes this not a simple project...
-Avi