A good way of shortening the boring daily commute is listening to an interesting podcast. Due to the poor quality of much of the talk radio in Ireland, I've found myself recently downloading more podcasts.
Of course, the BBC is always a great source, and Radio 4 and the World Service in particular have a number of excellent discussion and analysis programs available. Below I've included links to some shows I've lately been impressed by.
What else would p.ie users recommend?
BBC - Podcasts - A History of the World in 100 Objects
BBC - Podcasts - Americana: inside the USA
BBC - Podcasts - Analysis
BBC - Podcasts - Forum - A World of Ideas