Recommender systems in a travel guide suggest touristic sites a user may like. Typically, people are more willing to trust recommendations from people they know. We present a trust-based recommendation service for a mobile tourist guide that uses the notion of directly and indirectly trusted peers. The recommendations combine information about the peers’ ratings on sights, interpersonal trust and geographical constraints. We created two trust propagation models to spread trust information throughout the traveller peer group. Our prototype supports six trust-based, location-aware recommendation algorithms.