Harold,

In my experience the big problem with communication is there is too much focus on the technology used to get a message from a to b and not enough attention given to the quality of the message. Rambling unfocused emails, complex misunderstood phone discussions are just two examples.

Personally, I'd suggest you forgo the videos and podcasts -- unless you've got a message that needs visuals or audio. The time taken to master the technologies could be put to better use elsewhere.

Incidentally, your blog indicates you certainly don't have a problem with written communications.

From my experience most knowledge workers should focus on short, sharp nuggets of communication. Twitter is excellent practice.