Let the hive mind of Engadget get that for you.
"I need help! I want a small pocket camcorder but I'm not sure which one to get. I don't want to fall into the hype of the Flip because I worry two hours won't be enough. What should I be looking for when considering a small camcorder and where can I get a good quality one with expandable memory? Thanks!"
The SD to HD channel conversion for Comcast probably varies from area to area the way all the channels do. In my area, there is no simple algorithm - CBS and Fox are 29 and 25 for SD, respectively, and 214 and 213 for HD.