I have made some progress on notthere_ip today. First of all, I have changed the code to use DNS compression; this is done by having the answer be a compression pointer to the question, and doesn't require running the expensive DNS compression code.
Second of all, I have made my first pass at documenting this code. The writing needs to be proofread; I use "is" where I should have used "if" in one case, for example. That said, notthere_ip is now part of the mararc man page.
It can be downloaded at the usual place (that's a link to click on guys)