Had Ooma since the weekend - saw in the call log the same number popup once per day - called during the day when no one was home. Copied number and pasted in Google - discovered that this is one of those numbers for the "We can lower your interest rates" robocalls - so I immediately blacklisted it. You could offer a search option right within the callog to assist users with tracking down who is calling.
I was thinking to do this for only numbers that you don't already "trust" but Ooma doesn't support the concept of a white list yet. I wonder if they have any white list plans? Anyway.. I digress.
I like the suggestion.