I think it's important for you to try to figure out what it is you want to know. I've been on the same road trip for the pat 4 years (one week at a time) and for a while i was kind of doing this "Proust Questionnaire" thing (ala Vanity Fair) -sometimes i would predetermine the questions from that batch and sometimes i would have 2 standard q's and then have the rest on cards and let someone pick a card - leave it up to the "universe" to decide which other question they should answer.
i had a cousin on a few of these trips and she took the opportunity to ask people questions that we important to her (i.e. questions about community, healing...along those lines).
what is it that you personally really want to know about?