I pulled Bob Jenkins' superlative lookup3.c into ccan some time ago, and with the work on TDB2 (aka 64-bit TDB) I wondered if there was a 64-bit variant available. I didn't look hard enough: I should have checked his top-level page and seen lookup8.c before wasting his time with an email :(
I did note in my mail that since lookup3.c can return a pair of 32 bit numbers, I could combine those to get a 64 bit hash "but I wondered if it was possible to do better..."
His one-line reply was that he was working on a 128-bit hash now. Respectful and informative.
The gold standard test of online manners is how you respond to a dumb random email. A truly gracious gentleman/lady will respond as if you are far smarter far than you appear. Thanks Bob. And 128-bit; I'm a little stunned...