Andrew Simons (3 dan) is giving a series of audio lectures online as part of the BGA's Shodan Challenge. All are welcome to attend, the target audience is around 10 kyu to 1 kyu. They are fortnightly at 8pm on Thursdays in the British Room on KGS (http://www.gokgs.com) under the account 'Uberdude'. The next lesson is on 19th January and lessons will be announced on the gotalk mailing list (in case life interferes with the fortnightly schedule).
Each lecture looks at a topic, illustrating the concepts with examples from real games, and lasts about an hour. Past topics have included "Playing against the san-ren-sei", "Crosscuts", "The 4-4 attach-extend joseki", and "How to win by giving your opponent lots of territory". The next lesson will be "Probes", suggestions for future topics are welcome.