GeohashPhrase looks quite brilliant. Will there be an open source implementation? I hope so -- it's hard to see it gaining traction against w3w without it, and it is undeniably better.
Right now the problem is that we don't have anything more than a description of our idea to release...
In Python, the base32 to bytes exists in the standard library, and with an import[2] you can get the code to convert bytes to PGP word list. Literally 2 lines of code.
Partly, that means choosing words that are short, aurally clear, unambiguous, in common usage, etc.
It also means we need words that together form a sentence. Initially that means choosing a good sentence structure. Our is [1-Adjective 2-Noun 3-Verb 4-Adjective 5-Noun (6-Adjective) (7-Noun)]. Next, we have to choose words that are most often the part of speech for the dictionary they need to live in, since we'll never re-use a word.
Getting this dictionary together and having it good is a huge task. Of course we have a naive dictionary, but that's barely suitable for testing purposes.
I may choose to make the "docs" I've written available today in their rough state. That will explain things slightly more.
PGP word list already did the "short, aurally clear, unambiguous, in common usage, etc." pretty well. But the way they're structured doesn't create sentences, and I can see how creating sentences would be helpful.