[[Young_Zaphod_Plays_it_Safe?]] can now be found in The Salmon of Doubt.
The big questions surrounding this story seems to be about the escaped robot, and his/her identity. So who/what exactly is this? Good question. The reference to the shining city on a hill is probably a reference to Matthew 5:14. Some people also assume the "mystery person" in question is Jesus Christ. As YZPIS was originally published in The Utterly Utterly Merry Comic Relief Christmas Book, that would make sense.
However, Douglas Adams himself now claims that the mystery person is, in fact, Ronald Reagan. A short piece by Douglas in the compilation book The Wizards of Odd (which also features the entire story) quotes parts of the story as evidence to support this, so it seems even more feasible than any other explanation you might care to come up with.
Later publications of the story make it clear who DNA meant the person to be, by refering to it as a 'Reagan'.