Billboards advertise products on highways and city streets. These may simply be freestanding billboards or may be part of street furniture such as a bus shelter. Buses and taxis are often covered in adverts, while budget airlines sometimes allow advertising inside their planes. Adverts also appear in newspapers, magazines and sports programmes. Many stadiums have adverts set around them. Sports teams, tournaments, television programmes and public events may have a sponsor who is the main or sometimes only advertiser.