In reply to hfisher:
as mentionned, the campsites 'à la ferme' and the one on the moustier side of the village are nice and cheap and within easy access to the pizza-bus and bar
the very large campsite has less charme imo
for bivying: very nice spot when you continue up the road past the belvédères, at one point ( close to the highest elevation on the looproad) there s a dirtroad going right . you can't enter by car but there are very nice spots up there.
an other option is the 'terrain de l'amitié' informal campsite. on the way from the point sublimeto the couloir samson, once you leave the main road to go down to the parking, there's a small road down the left side where you can find a couple of tent sites. no equipment in place but calm