Got a call from this number on a phone which is on the federal do-not-call list. They didn't respond immediately, but after a few seconds a rep came on the line and stated he was calling for some energy company (unfortunately I forget the name). I didn't wait for the pitch.

Call at 2:15 PM on 4/13/2011, noone there

When you pick up the phone no one there just an open line

NEVER answer and the # is blocked when you try to call back

Caller did not respond immediately. When they did respond they stated the name of some kind of energy company - unfortunately I was busy and don't recall the name now. I told them to put me on their do-not-call list. Rep tried to keep me on the phone and I explained I was on the federal DNC, they then hung up.