Managing Sales Calls - how do you do it?

We're trying to adapt NetSuite to help us manage our call lists.  We are new to this, but on the face of it, there's no real way to manage calls in this way.

I know there is a way to schedule a call with someone, but this seems far too rigid, and a major pain in the butt for each call to be like an event or meeting.  What happens if you don't get to that call on that day?

We have created a custom field called "Follow Up Date" with the theory that we can then use it in searches.  Other criteria to tell who to call would be great too, though: like date of a customers last order, and how much it was for.  Even better would be to be able to compare it to their average ordering interval and average order amount, so we could see if it had been "a long time since they ordered" -- for that customer.