More anti-procrastination hacks

In my last post I mentioned three different anti-procrastination hacks that shared several similarities. Now, 43Folders has two new variants

• Jeff Covey, a 43Folder reader, shares his method, The Progressive Dash. It's the original Merlin Mann Dash combined with a system that automatically picks out next item that gets the 10 minutes treatment. Iterate until satisfied.
• Merlin Mann presents his variant, (10+2)*5, where each 10 minute dash is followed by a 2 minute break. Repeat 5 times until the hour is up.

I wonder if this constant starting and stopping is good? When will you let yourself sufficient time to get into the Flow? For more important tasks I feel that D. Keith Robinson suggestion of 60-120 minutes for each task is more appropriate.