In almost 100 episodes of awesomeness and epic rants, John Siracusa, the last real nerd out there, provided much insight on many, many topics around technology. I learned a ton about SSDs, programming languages, CPUs, the early days of Apple and much more. I had no idea of programming and many other topics, but through John's ability to explain stuff on an abstract level even enjoyed the very, very technical episodes. Just great.
A few of my favourite topics and may-be suggestions for you:
(If you're looking for a podcasting app for iOS now, I recommend Instacast).