"alex" == alex <alex@yuriev.com> writes:
alex> Just because free public dbs dont have that info does not alex> mean that it does not exist. i guess the question is, "how to ascertain the accuracy of the data?" if you have a collection of n known address to location mappings, evenly distributed over the address space, you'd want to approach one of the private db vendors and say, "do lookups on these n addresses and tell me the answers." if there's a good correlation between the known data and the answers, then it might make sense to purchase data [*] from those people. but. it is probably necessary to construct the set of control data by hand, which might be a big job. what is a sufficiently large n? for n sufficiently large, are the vendors likely to answer the question? i suspect that, in real life, it will come down to trusting the vendors' assertion that their data is accurate... -w [*] purchase data!?!? doesn't information want to be free? or is that passé? oh well... -- William Waites <ww@styx.org> Idiosyntactix Research Laboratories http://www.irl.styx.org