Q: Is there a quick way to pull a list of everyone I haven't called in the last "X" days?
A: There are a bunch of ways to do this- but EVERYTHING hinges on whether or not you record your last call date on your contact record.
To do this without a Workflow, go to contacts and use the filter:
How time saving cool is THAT?! Then, RV will tell you to call again, the number of days you said to call after today (the day you called)