Denpasar is a city on Bali. Although it is one of the most touristy places of Indonesia, it is still possible to hitchhike even within the city if you speak some bahasa indonesia. You only need to wait at a traffic light for a pick up and ask if you can jump on the back. ("salamat x, boleh ikut di belakang? mau ikut sedikit saja! terima kasih!). Be quick and now where you have to jump off.