What are some good interval workouts based on time or heart rate?

Question

what are some good interval workouts based on time or heart rate, i live next to mountains and climb everyday

Answer 1

jump rope

Answer 2

Go until you can't go anymore, stop and rest then repeat.

Answer 3

Its easier to do on a trainer than it is outside, as you're not limited by terrain or traffic.   Indoors, I just aim for intervals that mimic what I do in the pool or on the track.  

For a more comprehensive treatment specific to cycling, I recommend "The Heart Rate Monitor Book" by Sally Edwards.