Since I've been working from home full time, I've really gotten addicted to IT Conversations. The talks make really good background for coding. Some are boring and I generally pick and choose ones that interest me. Here are a few I've liked lately:

R0ml Lefkowitz, Chief Technical Architect, AT&T Wireless

Jonathan Schwartz, President, Sun Microsystems

Philip Greenspun, Software Engineering

Update:
Clay Shirky, Ontology is Overrated (forgot this one)