Yes, WhoKnows supports lists that you can add or remove profiles from for easier access. You can add profiles to a list multiple ways.
For any profile you are viewing you can add that profile to an existing or new list.
For any profile in the search results, you can also add a profile to the list.
You can also add multiple profiles at once to a list by selecting them in the search results, then clicking the arrow next to the Contact All button to add all of them to a list.