Couchsurfing is the practice of sleeping at the houses of several different people for a periodof time without paying.
He spent a few months couchsurfing.
couchsurfing in British English
(ˈkaʊtʃˌsɜːfɪŋ)
noun
the practice of sleeping overnight in the houses of friends or fellow members of a social network, esp as an alternative to staying in hotels, hostels, etc