I really hate saying numbers in the HFL coz sometimes it doesn't understand me correctly. Well today on my way to lunch I started to play with it.

If you hit the HFL button and say a couple of numbers, wait for it to respond. It will then give you a "continue to add number" option. Say "continue" and you can add to the numbers you've just said. You can also cancel out the next set of numbers and go back to the previous set. I haven't tried it on the Phonebook section yet. Hope that option is there too.