Intervals!

I've heard and read this everywhere for months now: Do your cardio in intervals because it is way more effective. As I was growing increasingly weary of doing my 30 min. runs on the treadmill, I decided it was time for a change and the change came in the form of intervals.
It's only been two weeks of this, so I can't really tell whether I am running way more effectively, as it has been heralded by fans of the intervals way. What I can attest to is that it is psychologically refreshing. Instead of watching 30 minutes tick away, I've broken it down in my head to three sets of 10 minutes, and I try to work my speed up to its maximum by the end of each third. So in other words, I want to run at least at an 8.0 pace as my maximum, and I therefore try to reach and sustain that, starting from 30, by minute 20, minute 10 and 0. In order to progress, I've played around with trying to sustain the 8.0 pace for longer and longer, so now I am running at or above an 8.0 from minute 23-minute 20, minute 13-minute 10, etc.
I guess each person has to find what works best for them. This, more than anything, has kept my brain occupied in a different way during my runs, which is a much needed change!