For some reason, erasable pens always evoke for me memories of my 3rd and 4th grade teacher, Mrs. Covington. I've used them often since, but in my mind they are indelibly linked with that class.
She was brilliant. We got to set our own spelling words each week and then tested each other. We got to dress in white "lab coats" and do "science experiments," which we then wrote up in our journals, describing each piece of the scientific method.
Her class wasn't like other classes. We didn't sit at desks all day, doing worksheets. I remember that when we would give each other our spelling tests, Laurie and I (my friend, who I just now remembered! I haven't seen her since 5th grade) would sit under the table to do it.
We were up and about, using our hands and all of our senses to understand what was going on. We had a considerable amount of autonomy in deciding what we wanted to study and how we wanted to study it. We voted on whether we wanted to focus on Egypt or some other places in social studies (Egypt won, so I don't remember the other options we had :-)).
Sorry for the lapse into nostalgia. When you're looking for procrastination, something as simple as erasable pens can keep you from working.