This confused me as well after switching to 360. If you are using the 'Shared' profile you can tap in channel number 101 and be taken there. Same for any other channel, providing you know the number in the guide. On my personal profile, I have assigned BBC One the number 1, so it's a single button press. More simply I use the voice command 'Top' and it takes me to the beginning of the list, or anywhere else on the guide I wish to go to. After a while it becomes second nature.