On one of the mailing lists I'm on, a member posted her snailmail address, fairly confident that no one could find her place, living way out in the country like she does.
Five minutes at MapQuest [1] and I had directions from my house in Lower Sheol to her house in Wisconsin (something like 1,750 miles door to door).
I also found another site, Etak, [2] which does the same thing (pretty much got the same directions) plus gives out latitude and longitude information as well.
I've yet to hear back to see if the directions were any good or not.