We use lists for prospecting before moving constituents into portfolios. There is, however, no way to track which records have been reviewed or any intermediate status before assigning to a fundraiser's portfolio. The ability to add flags to records in lists -- and to filter by those flags -- would make the lists much more useful.
Thanks, Jarod. Since submitting this idea, I have begun using custom fields (e.g. “inventory status”) for this purpose with good success. A flag would be a quick and helpful visual for temporarily noting records that you want to return to, but the custom field at least allows you to sort the list by status.
Just a quick thought - if you have the Prospect module you could absolutely use "Prospect status" for this. Otherwise, I would recommend creating a custom field to track this value which can be filtered by and displayed in the List you are using.
I hope that helps! If not, please do let me know if I'm missing a nuance to the request.