The Kyle Lake Center for Effective Preaching at George W. Truett Seminary. They've started hosting several events a year. When I can, I attend. When I can't, I watch online. Currently they have the entire Will Willimon and Haddon Robinson Lectures available with more on the way.
To listen to the first Willimon lecture, click through the jump.
Here's the first session of the Willimon lectures. The first little bit involves discussions relevant to those at the conference and may not interest you, but be patient, this gets good. Really good at the end. Worth a listen.