National Geographic HDOf all the HD channels out there that aren't offered by most providers, it seems that National Geographic HD might be the most sought after. We have some good news for Cox Communications subscribers, 'cause they're going to start rolling it out this year and expect all HD subscribers to have it by 2009. Unfortunately for most, Cox isn't the biggest provider in the country, so the rest of us will have to wait -- or if you can't wait, just switch to DISH Network.