In Tallinn if you take a bus, trolleybus or tram, you can buy a ticket from a driver. Remember to buy it immediately when you are going in, cause driver sells tickets only at the stops.
It's more expensive to buy from a driver than from a news-stand, for example R-kiosk. The ticket is called "talong" or "pilet" and one journey in Tallinn costs 13 EEK, from driver 20 EEK. You have to stamp it in the ticket machine inside the vehicle.
All people over 65 year (also people form foreign countries) can travel free in busses, trolleybuses and trams. But you have to have a document to prove it like passport.
Official website of bus transport
All schedules of busses, trams and trolleybuses:
Indietro: By express bus
Avanti: By ship