Currently, you can't customize the channel selection that you see in your listings, but you can search your listings to bring up specific combinations of days (up to one week in advance), times, and categories of program.

For example, if you'd like to see if there are any westerns playing on Saturday, you would select "Sat," your time preference, and "Western" in the pull-down menus above the listings and click "Go!" A selection of all the relevant programs appears.