Podcasts mean you have no excuse to be bored ever again. You can study ancient Roman history while standing in a queue at the bank; learn Mandarin while doing the ironing and listen to your favourite novelist field hard questions while on the treadmill at the gym. Podcasts have opened up universities, time-shifted radio and created new audiences for comedy, poetry and music. University lecturers and high school students, wine buffs and tech-heads are all uploading information, opinions and creative work. Most striking of all, podcasts are free – and legally so.