Here are some links to a few websites that offer podcasts related to prayer:
Meditations from Carmel: The site is from the Secular Carmelites (OCDS) in St. Louis, Missouri. The podcasts include meditations of 1.5 to 5 minutes in length, taken from the writings of the Carmelite saints.
Pray as You Go: The site is from the Jesuits in Britain. The podcasts provide a new prayer session of 10 to 12 minutes for each day. The page also offers instruction in preparing to pray.
Pray the News: The site is from the Carmelites of Indianapolis (OCD) who have provided the Pray the News website for a long time now. The podcast is new, and the first podcast is now available, on the subject of what praying the news is all about.