What podcasts are you listening to?

I’ve never got into podcasts, I’m not even sure what they are? Are they radio shows that include video, or TV shows, on the Internet? I guess like anything else they can have their own style and substance.

I don’t have an iPhone, do you need one of those to listen to podcasts? Are they short programmes or long ones. If you call something a podcast does that mean it really is? I watch lots of videos, because I’m a visual person, and although I can pick up a tune or understand an argument, I’m not necessarily an aural person. I’m not into music, not in a big way, I tolerate it, and unless it’s a particular classical style I can pretty much leave it.

Please give some examples of good podcasts, and I will try and catch them?