Here are the two main posts tagged with Meditation, and here are the three discussion posts. Also see DavidM's posts (1 and 2, 3 appears to have never been written) and a more recent thread about it. I missed a few posts you can find by searching for meditation.

The impression I get is that there are several people who find it interesting/useful, but it hasn't penetrated deeply enough to become part of the LW core. (I personally don't meditate, after a few initial tests suggested that noticeable effects would take far more time input than I was willing to give it.)