Your are correct about craigslist. It can be spam at times, but does have opportunities every now and then. I've noticed that looking at my local craigslist. Something like the general labor can have daily things going. I plan to check it if staying in the same are for several days.
By searching here, I've seen some volunteering ideas listed. The main one was WWOOFing. I plan to sign up soon and see if any spots are open along the first part of my route. I was curious if anyone here had done that as it is a small fee to sign up and view the farm listings.