We do a lot of interval training at work.
It's absolutely fanastic!
I usually get people doing 1 min hard, 1 min not-so hard on the treadmill and get them to alternate between the 2... like when I'm training I usually do 1 min @ 13km/hr, then the next min @ 11km/hr and then back to the 13km etc etc
We also do it on the spin bikes, eg sprint for 10 seconds, relax the pace for 10 seconds - do that for 1 minute and then start sprint for 15 seconds, relax the pace for 15 seconds.
Also on the rower - at the start of every minute, a 15 second sprint
Can do the same on the climber.
It mixes it up a bit and changes the intensity for people without absolutely killing them!!
I loves interval training
Not sure about this 8 second/12 second thingo! That could get annoying to keep track of!